From 0affcf610822aa1863d3bfbeb9e2d9cba643746f Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Fri, 10 Apr 2026 16:06:58 +0300
Subject: [PATCH 01/24] Allow running on Windows ARM64

---
 src/briefcase/platforms/windows/__init__.py    | 18 ++++++++----------
 src/briefcase/platforms/windows/app.py         |  4 +++-
 .../platforms/windows/visualstudio.py          |  5 ++++-
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/briefcase/platforms/windows/__init__.py b/src/briefcase/platforms/windows/__init__.py
index 9ae3cd5ff0..fab8b50b10 100644
--- a/src/briefcase/platforms/windows/__init__.py
+++ b/src/briefcase/platforms/windows/__init__.py
@@ -79,7 +79,7 @@ def bundle_package_executable_path(self, app):
             return f"{app.formal_name}.exe"
 
     def bundle_package_path(self, app):
-        return self.bundle_path(app) / self.packaging_root
+        return self.bundle_path(app) / self.packaging_root()
 
     def binary_path(self, app):
         return self.package_path(app) / self.package_executable_path(app)
@@ -90,10 +90,7 @@ def distribution_path(self, app):
 
     def verify_host(self):
         super().verify_host()
-        # The stub app only supports x86-64 right now, and our VisualStudio and WiX code
-        # is the same (#1887). However, we can package an external x86-64 app on any
-        # build machine.
-        if self.tools.host_arch != "AMD64":
+        if self.tools.host_arch not in ("AMD64", "ARM64"):
             if all(app.external_package_path for app in self.apps.values()):
                 if not self.is_clone:
                     self.console.warning(f"""
@@ -101,11 +98,11 @@ def verify_host(self):
 ** WARNING: Possible architecture mismatch                             **
 *************************************************************************
 
-The build machine is {self.tools.host_arch}, but Briefcase on Windows currently only
-supports x86-64 installers.
+The build machine is {self.tools.host_arch}, but Briefcase on Windows only
+supports x86-64 and ARM64 installers.
 
 You are responsible for ensuring that the content of external_package_path
-is compatible with x86-64.
+is compatible with supported platforms.
 
 *************************************************************************
 """)
@@ -127,7 +124,8 @@ def verify_host(self):
 
 class WindowsCreateCommand(CreateCommand):
     def support_package_filename(self, support_revision):
-        return f"python-{self.python_version_tag}.{support_revision}-embed-amd64.zip"
+        arch = self.tools.host_arch.lower()
+        return f"python-{self.python_version_tag}.{support_revision}-embed-{arch}.zip"
 
     def support_package_url(self, support_revision):
         micro = re.match(r"\d+", str(support_revision)).group(0)
@@ -594,7 +592,7 @@ def _package_msi(self, app):
                         "-ext",
                         self.tools.wix.ext_path("UI"),
                         "-arch",
-                        "x64",  # Default is x86, regardless of the build machine.
+                        "arm64" if self.tools.host_arch == "ARM64" else "x64",
                         f"{app.app_name}.wxs",
                         "-loc",
                         "unicode.wxl",
diff --git a/src/briefcase/platforms/windows/app.py b/src/briefcase/platforms/windows/app.py
index 06dbd079fa..0ddbd548a5 100644
--- a/src/briefcase/platforms/windows/app.py
+++ b/src/briefcase/platforms/windows/app.py
@@ -23,9 +23,11 @@
 
 class WindowsAppMixin(WindowsMixin):
     output_format = "app"
-    packaging_root = Path("src")
     supports_external_packaging = True
 
+    def packaging_root(self):
+        return Path("src")
+
     def project_path(self, app):
         return self.bundle_path(app)
 
diff --git a/src/briefcase/platforms/windows/visualstudio.py b/src/briefcase/platforms/windows/visualstudio.py
index b7275fe3b2..45686e657a 100644
--- a/src/briefcase/platforms/windows/visualstudio.py
+++ b/src/briefcase/platforms/windows/visualstudio.py
@@ -21,7 +21,10 @@
 
 class WindowsVisualStudioMixin(WindowsMixin):
     output_format = "VisualStudio"
-    packaging_root = Path("x64/Release")
+
+    def packaging_root(self):
+        arch = "ARM" if self.tools.host_arch == "ARM64" else "x64"
+        return Path(f"{arch}/Release")
 
     def project_path(self, app):
         return self.bundle_path(app) / f"{app.formal_name}.sln"

From dc9b6169536566977a2ada43745ac0fe824ac909 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Fri, 10 Apr 2026 18:13:32 +0300
Subject: [PATCH 02/24] Fix VS packaging root for ARM

---
 src/briefcase/platforms/windows/visualstudio.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/briefcase/platforms/windows/visualstudio.py b/src/briefcase/platforms/windows/visualstudio.py
index 45686e657a..b6df036cb6 100644
--- a/src/briefcase/platforms/windows/visualstudio.py
+++ b/src/briefcase/platforms/windows/visualstudio.py
@@ -23,7 +23,7 @@ class WindowsVisualStudioMixin(WindowsMixin):
     output_format = "VisualStudio"
 
     def packaging_root(self):
-        arch = "ARM" if self.tools.host_arch == "ARM64" else "x64"
+        arch = "ARM64" if self.tools.host_arch == "ARM64" else "x64"
         return Path(f"{arch}/Release")
 
     def project_path(self, app):

From 9a0e6355a3f98296e0e1bab07844fef369ffd09b Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Fri, 10 Apr 2026 18:16:25 +0300
Subject: [PATCH 03/24] Pass platform to MSBuild

---
 src/briefcase/platforms/windows/visualstudio.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/briefcase/platforms/windows/visualstudio.py b/src/briefcase/platforms/windows/visualstudio.py
index b6df036cb6..22bef36339 100644
--- a/src/briefcase/platforms/windows/visualstudio.py
+++ b/src/briefcase/platforms/windows/visualstudio.py
@@ -60,6 +60,7 @@ def build_app(self, app: BaseConfig, **kwargs):
 
         with self.console.wait_bar("Building solution..."):
             try:
+                arch = "ARM64" if self.tools.host_arch == "ARM64" else "x64"
                 self.tools.subprocess.run(
                     [
                         self.tools.visualstudio.msbuild_path,
@@ -68,6 +69,7 @@ def build_app(self, app: BaseConfig, **kwargs):
                         "-property:RestorePackagesConfig=true",
                         f"-target:{app.formal_name}",
                         "-property:Configuration=Release",
+                        f"-property:Platform={arch}",
                         (
                             "-verbosity:detailed"
                             if self.console.is_deep_debug

From 86bd5dacda9753af73e9964e4feb325d7e628abf Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Fri, 10 Apr 2026 20:47:50 +0300
Subject: [PATCH 04/24] Construct correct stub binary filename for ARM

---
 src/briefcase/commands/create.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/briefcase/commands/create.py b/src/briefcase/commands/create.py
index 937bbf8f04..98c6f1a658 100644
--- a/src/briefcase/commands/create.py
+++ b/src/briefcase/commands/create.py
@@ -123,7 +123,15 @@ def support_package_url(self, support_revision: str) -> str:
     def stub_binary_filename(self, support_revision: str, is_console_app: bool) -> str:
         """The filename for the stub binary."""
         stub_type = "Console" if is_console_app else "GUI"
-        return f"{stub_type}-Stub-{self.python_version_tag}-b{support_revision}.zip"
+        win_arm_suffix = (
+            "-arm"
+            if self.tools.host_os == "Windows" and self.tools.host_arch == "ARM64"
+            else ""
+        )
+        return (
+            f"{stub_type}-Stub-{self.python_version_tag}-b{support_revision}"
+            f"{win_arm_suffix}.zip"
+        )
 
     def stub_binary_url(self, support_revision: str, is_console_app: bool) -> str:
         """The URL of the stub binary to use for apps of this type."""

From 2c04b8021d963601575a2e09ee9b307bcc7188d5 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Mon, 13 Apr 2026 12:51:51 +0300
Subject: [PATCH 05/24] Refactor platform checks

---
 src/briefcase/platforms/windows/__init__.py     | 5 ++++-
 src/briefcase/platforms/windows/visualstudio.py | 6 ++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/briefcase/platforms/windows/__init__.py b/src/briefcase/platforms/windows/__init__.py
index fab8b50b10..35f70cb573 100644
--- a/src/briefcase/platforms/windows/__init__.py
+++ b/src/briefcase/platforms/windows/__init__.py
@@ -88,6 +88,9 @@ def distribution_path(self, app):
         suffix = "zip" if app.packaging_format == "zip" else "msi"
         return self.dist_path / f"{app.formal_name}-{app.version}.{suffix}"
 
+    def windows_arch(self):
+        return "ARM64" if self.tools.host_arch == "ARM64" else "x64"
+
     def verify_host(self):
         super().verify_host()
         if self.tools.host_arch not in ("AMD64", "ARM64"):
@@ -592,7 +595,7 @@ def _package_msi(self, app):
                         "-ext",
                         self.tools.wix.ext_path("UI"),
                         "-arch",
-                        "arm64" if self.tools.host_arch == "ARM64" else "x64",
+                        app.windows_arch().lower(),
                         f"{app.app_name}.wxs",
                         "-loc",
                         "unicode.wxl",
diff --git a/src/briefcase/platforms/windows/visualstudio.py b/src/briefcase/platforms/windows/visualstudio.py
index 22bef36339..6a82a320f7 100644
--- a/src/briefcase/platforms/windows/visualstudio.py
+++ b/src/briefcase/platforms/windows/visualstudio.py
@@ -23,8 +23,7 @@ class WindowsVisualStudioMixin(WindowsMixin):
     output_format = "VisualStudio"
 
     def packaging_root(self):
-        arch = "ARM64" if self.tools.host_arch == "ARM64" else "x64"
-        return Path(f"{arch}/Release")
+        return Path(f"{self.windows_arch()}/Release")
 
     def project_path(self, app):
         return self.bundle_path(app) / f"{app.formal_name}.sln"
@@ -60,7 +59,6 @@ def build_app(self, app: BaseConfig, **kwargs):
 
         with self.console.wait_bar("Building solution..."):
             try:
-                arch = "ARM64" if self.tools.host_arch == "ARM64" else "x64"
                 self.tools.subprocess.run(
                     [
                         self.tools.visualstudio.msbuild_path,
@@ -69,7 +67,7 @@ def build_app(self, app: BaseConfig, **kwargs):
                         "-property:RestorePackagesConfig=true",
                         f"-target:{app.formal_name}",
                         "-property:Configuration=Release",
-                        f"-property:Platform={arch}",
+                        f"-property:Platform={self.windows_arch()}",
                         (
                             "-verbosity:detailed"
                             if self.console.is_deep_debug

From aa32d1c73a645b3141d10ab242f4dd099d3c35a9 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Mon, 13 Apr 2026 12:56:44 +0300
Subject: [PATCH 06/24] Add changes note

---
 changes/1887.feature.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changes/1887.feature.md

diff --git a/changes/1887.feature.md b/changes/1887.feature.md
new file mode 100644
index 0000000000..5371449d65
--- /dev/null
+++ b/changes/1887.feature.md
@@ -0,0 +1 @@
+Windows on ARM64 is now supported.

From 2b9ca766a7c26bba187997c7096bbb8fff481363 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Mon, 13 Apr 2026 13:03:51 +0300
Subject: [PATCH 07/24] Add windows-11-arm runner

---
 .github/workflows/ci.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0ae7f1ed3c..624d5dce3b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -235,7 +235,7 @@ jobs:
       fail-fast: false
       matrix:
         framework: [ "toga", "pyside6", "pygame", "console" ]
-        runner-os: [ "macos-15-intel", "macos-latest", "ubuntu-24.04", "ubuntu-24.04-arm", "windows-latest" ]
+        runner-os: [ "macos-15-intel", "macos-latest", "ubuntu-24.04", "ubuntu-24.04-arm", "windows-latest", "windows-11-arm"]
 
   verify-apps:
     name: Build app
@@ -250,4 +250,4 @@ jobs:
       fail-fast: false
       matrix:
         framework: [ "toga", "pyside6", "pygame", "console" ]
-        runner-os: [ "macos-15-intel", "macos-15", "ubuntu-24.04", "ubuntu-24.04-arm", "windows-latest" ]
+        runner-os: [ "macos-15-intel", "macos-15", "ubuntu-24.04", "ubuntu-24.04-arm", "windows-latest", "windows-11-arm" ]

From aece50500e9dc985740e98f6303a096299a8e80d Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Mon, 13 Apr 2026 13:05:57 +0300
Subject: [PATCH 08/24] Add suffix for amd64

---
 src/briefcase/commands/create.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/briefcase/commands/create.py b/src/briefcase/commands/create.py
index 98c6f1a658..d0e9244749 100644
--- a/src/briefcase/commands/create.py
+++ b/src/briefcase/commands/create.py
@@ -123,14 +123,14 @@ def support_package_url(self, support_revision: str) -> str:
     def stub_binary_filename(self, support_revision: str, is_console_app: bool) -> str:
         """The filename for the stub binary."""
         stub_type = "Console" if is_console_app else "GUI"
-        win_arm_suffix = (
-            "-arm"
-            if self.tools.host_os == "Windows" and self.tools.host_arch == "ARM64"
+        win_suffix = (
+            f"-{self.tools.host_arch.lower()}"
+            if self.tools.host_os == "Windows"
             else ""
         )
         return (
             f"{stub_type}-Stub-{self.python_version_tag}-b{support_revision}"
-            f"{win_arm_suffix}.zip"
+            f"{win_suffix}.zip"
         )
 
     def stub_binary_url(self, support_revision: str, is_console_app: bool) -> str:

From 209724f995d7971a43eccc4f89307d2c4f241b95 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Mon, 13 Apr 2026 13:41:08 +0300
Subject: [PATCH 09/24] Update tests

---
 src/briefcase/platforms/windows/__init__.py        | 4 ++--
 src/briefcase/platforms/windows/visualstudio.py    | 4 ++--
 tests/platforms/windows/app/create/test_create.py  | 6 +++---
 tests/platforms/windows/visualstudio/test_build.py | 1 +
 4 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/briefcase/platforms/windows/__init__.py b/src/briefcase/platforms/windows/__init__.py
index 35f70cb573..7cd889940c 100644
--- a/src/briefcase/platforms/windows/__init__.py
+++ b/src/briefcase/platforms/windows/__init__.py
@@ -88,7 +88,7 @@ def distribution_path(self, app):
         suffix = "zip" if app.packaging_format == "zip" else "msi"
         return self.dist_path / f"{app.formal_name}-{app.version}.{suffix}"
 
-    def windows_arch(self):
+    def architecture(self):
         return "ARM64" if self.tools.host_arch == "ARM64" else "x64"
 
     def verify_host(self):
@@ -595,7 +595,7 @@ def _package_msi(self, app):
                         "-ext",
                         self.tools.wix.ext_path("UI"),
                         "-arch",
-                        app.windows_arch().lower(),
+                        self.architecture().lower(),
                         f"{app.app_name}.wxs",
                         "-loc",
                         "unicode.wxl",
diff --git a/src/briefcase/platforms/windows/visualstudio.py b/src/briefcase/platforms/windows/visualstudio.py
index 6a82a320f7..c9ee84ee0d 100644
--- a/src/briefcase/platforms/windows/visualstudio.py
+++ b/src/briefcase/platforms/windows/visualstudio.py
@@ -23,7 +23,7 @@ class WindowsVisualStudioMixin(WindowsMixin):
     output_format = "VisualStudio"
 
     def packaging_root(self):
-        return Path(f"{self.windows_arch()}/Release")
+        return Path(f"{self.architecture()}/Release")
 
     def project_path(self, app):
         return self.bundle_path(app) / f"{app.formal_name}.sln"
@@ -67,7 +67,7 @@ def build_app(self, app: BaseConfig, **kwargs):
                         "-property:RestorePackagesConfig=true",
                         f"-target:{app.formal_name}",
                         "-property:Configuration=Release",
-                        f"-property:Platform={self.windows_arch()}",
+                        f"-property:Platform={self.architecture()}",
                         (
                             "-verbosity:detailed"
                             if self.console.is_deep_debug
diff --git a/tests/platforms/windows/app/create/test_create.py b/tests/platforms/windows/app/create/test_create.py
index 61afc1fe80..c57c933ec2 100644
--- a/tests/platforms/windows/app/create/test_create.py
+++ b/tests/platforms/windows/app/create/test_create.py
@@ -28,9 +28,9 @@ def test_unsupported_host_os(create_command, host_os):
         create_command()
 
 
-@pytest.mark.parametrize("host_arch", ["i686", "ARM64", "wonky"])
+@pytest.mark.parametrize("host_arch", ["i686", "wonky"])
 def test_unsupported_arch(create_command, host_arch, first_app_config):
-    """Internal apps can only be developed on x86-64."""
+    """Internal apps can only be developed on x86-64 and ARM64."""
     create_command.tools.host_os = "Windows"
     create_command.tools.host_arch = host_arch
     create_command.apps["first"] = first_app_config
@@ -42,7 +42,7 @@ def test_unsupported_arch(create_command, host_arch, first_app_config):
         create_command.verify_host()
 
 
-@pytest.mark.parametrize("host_arch", ["i686", "ARM64", "wonky"])
+@pytest.mark.parametrize("host_arch", ["i686", "wonky"])
 def test_unsupported_arch_external(create_command, host_arch, first_app_config, capsys):
     """External apps can be built on a different architecture, with a warning."""
     create_command.tools.host_os = "Windows"
diff --git a/tests/platforms/windows/visualstudio/test_build.py b/tests/platforms/windows/visualstudio/test_build.py
index 7c6681ed1f..4d56a0f4f3 100644
--- a/tests/platforms/windows/visualstudio/test_build.py
+++ b/tests/platforms/windows/visualstudio/test_build.py
@@ -65,6 +65,7 @@ def test_build_app(build_command, first_app_config, tool_debug_mode, tmp_path):
                     "-property:RestorePackagesConfig=true",
                     "-target:First App",
                     "-property:Configuration=Release",
+                    f"-property:Platform={build_command.architecture()}",
                     "-verbosity:detailed" if tool_debug_mode else "-verbosity:normal",
                 ],
                 check=True,

From 873f553df41c51caa5950a57c1d437ac938c1e69 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Mon, 13 Apr 2026 13:49:56 +0300
Subject: [PATCH 10/24] Replace hardcoded amd64 suffix in tests

---
 tests/platforms/windows/app/create/test_create.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/platforms/windows/app/create/test_create.py b/tests/platforms/windows/app/create/test_create.py
index c57c933ec2..32cc356f13 100644
--- a/tests/platforms/windows/app/create/test_create.py
+++ b/tests/platforms/windows/app/create/test_create.py
@@ -162,7 +162,7 @@ def test_support_package_url(
     expected_link = (
         f"https://www.python.org/ftp/python"
         f"/{sys.version_info.major}.{sys.version_info.minor}.{micro}"
-        f"/python-{sys.version_info.major}.{sys.version_info.minor}.{revision}-embed-amd64.zip"
+        f"/python-{sys.version_info.major}.{sys.version_info.minor}.{revision}-embed-{create_command.tools.host_arch.lower()}.zip"
     )
     assert create_command.support_package_url(revision) == expected_link
 

From c25b340f0d64a7e48d2617318a1dc213c0b9523d Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Mon, 13 Apr 2026 15:01:18 +0300
Subject: [PATCH 11/24] Update platform support tables

---
 docs/en/reference/platforms/index.md         | 4 ++--
 docs/en/reference/platforms/windows/index.md | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/docs/en/reference/platforms/index.md b/docs/en/reference/platforms/index.md
index b3aa540f32..439ad98711 100644
--- a/docs/en/reference/platforms/index.md
+++ b/docs/en/reference/platforms/index.md
@@ -153,7 +153,7 @@
 <td></td>
 <td></td>
 <td colspan="2">{{ ci_tested }}</td>
-<td colspan="2"></td>
+<td colspan="2">{{ ci_tested }}</td>
 <td></td>
 <td></td>
 <td></td>
@@ -165,7 +165,7 @@
 <td></td>
 <td></td>
 <td colspan="2">{{ ci_tested }}</td>
-<td colspan="2"></td>
+<td colspan="2">{{ ci_tested }}</td>
 <td></td>
 <td></td>
 <td></td>
diff --git a/docs/en/reference/platforms/windows/index.md b/docs/en/reference/platforms/windows/index.md
index 8c3e0f3abc..aac47285eb 100644
--- a/docs/en/reference/platforms/windows/index.md
+++ b/docs/en/reference/platforms/windows/index.md
@@ -41,7 +41,7 @@
 <td></td>
 <td></td>
 <td colspan="2">{{ ci_tested }}</td>
-<td colspan="2"></td>
+<td colspan="2">{{ ci_tested }}</td>
 <td></td>
 <td></td>
 <td></td>

From 5adf8a4e19ad4503e74c34604337e6338d60d3a6 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Tue, 14 Apr 2026 05:29:05 +0300
Subject: [PATCH 12/24] Rename to vscode_platform and make a property

---
 src/briefcase/platforms/windows/__init__.py        | 5 +++--
 src/briefcase/platforms/windows/visualstudio.py    | 4 ++--
 tests/platforms/windows/visualstudio/test_build.py | 2 +-
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/briefcase/platforms/windows/__init__.py b/src/briefcase/platforms/windows/__init__.py
index 7cd889940c..c3bfdf51e3 100644
--- a/src/briefcase/platforms/windows/__init__.py
+++ b/src/briefcase/platforms/windows/__init__.py
@@ -88,7 +88,8 @@ def distribution_path(self, app):
         suffix = "zip" if app.packaging_format == "zip" else "msi"
         return self.dist_path / f"{app.formal_name}-{app.version}.{suffix}"
 
-    def architecture(self):
+    @property
+    def vscode_platform(self):
         return "ARM64" if self.tools.host_arch == "ARM64" else "x64"
 
     def verify_host(self):
@@ -595,7 +596,7 @@ def _package_msi(self, app):
                         "-ext",
                         self.tools.wix.ext_path("UI"),
                         "-arch",
-                        self.architecture().lower(),
+                        self.vscode_platform.lower(),
                         f"{app.app_name}.wxs",
                         "-loc",
                         "unicode.wxl",
diff --git a/src/briefcase/platforms/windows/visualstudio.py b/src/briefcase/platforms/windows/visualstudio.py
index c9ee84ee0d..206d2193e4 100644
--- a/src/briefcase/platforms/windows/visualstudio.py
+++ b/src/briefcase/platforms/windows/visualstudio.py
@@ -23,7 +23,7 @@ class WindowsVisualStudioMixin(WindowsMixin):
     output_format = "VisualStudio"
 
     def packaging_root(self):
-        return Path(f"{self.architecture()}/Release")
+        return Path(f"{self.vscode_platform}/Release")
 
     def project_path(self, app):
         return self.bundle_path(app) / f"{app.formal_name}.sln"
@@ -67,7 +67,7 @@ def build_app(self, app: BaseConfig, **kwargs):
                         "-property:RestorePackagesConfig=true",
                         f"-target:{app.formal_name}",
                         "-property:Configuration=Release",
-                        f"-property:Platform={self.architecture()}",
+                        f"-property:Platform={self.vscode_platform}",
                         (
                             "-verbosity:detailed"
                             if self.console.is_deep_debug
diff --git a/tests/platforms/windows/visualstudio/test_build.py b/tests/platforms/windows/visualstudio/test_build.py
index 4d56a0f4f3..7ca0327a3d 100644
--- a/tests/platforms/windows/visualstudio/test_build.py
+++ b/tests/platforms/windows/visualstudio/test_build.py
@@ -65,7 +65,7 @@ def test_build_app(build_command, first_app_config, tool_debug_mode, tmp_path):
                     "-property:RestorePackagesConfig=true",
                     "-target:First App",
                     "-property:Configuration=Release",
-                    f"-property:Platform={build_command.architecture()}",
+                    f"-property:Platform={build_command.vscode_platform}",
                     "-verbosity:detailed" if tool_debug_mode else "-verbosity:normal",
                 ],
                 check=True,

From 1f923fb61f05824c19cc28bd197d11b268208bd6 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Tue, 14 Apr 2026 05:35:25 +0300
Subject: [PATCH 13/24] Convert packaging_root to a property

---
 src/briefcase/platforms/windows/__init__.py     | 2 +-
 src/briefcase/platforms/windows/app.py          | 1 +
 src/briefcase/platforms/windows/visualstudio.py | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/briefcase/platforms/windows/__init__.py b/src/briefcase/platforms/windows/__init__.py
index c3bfdf51e3..04003fe529 100644
--- a/src/briefcase/platforms/windows/__init__.py
+++ b/src/briefcase/platforms/windows/__init__.py
@@ -79,7 +79,7 @@ def bundle_package_executable_path(self, app):
             return f"{app.formal_name}.exe"
 
     def bundle_package_path(self, app):
-        return self.bundle_path(app) / self.packaging_root()
+        return self.bundle_path(app) / self.packaging_root
 
     def binary_path(self, app):
         return self.package_path(app) / self.package_executable_path(app)
diff --git a/src/briefcase/platforms/windows/app.py b/src/briefcase/platforms/windows/app.py
index 0ddbd548a5..0559bdae95 100644
--- a/src/briefcase/platforms/windows/app.py
+++ b/src/briefcase/platforms/windows/app.py
@@ -25,6 +25,7 @@ class WindowsAppMixin(WindowsMixin):
     output_format = "app"
     supports_external_packaging = True
 
+    @property
     def packaging_root(self):
         return Path("src")
 
diff --git a/src/briefcase/platforms/windows/visualstudio.py b/src/briefcase/platforms/windows/visualstudio.py
index 206d2193e4..5e61a46357 100644
--- a/src/briefcase/platforms/windows/visualstudio.py
+++ b/src/briefcase/platforms/windows/visualstudio.py
@@ -22,6 +22,7 @@
 class WindowsVisualStudioMixin(WindowsMixin):
     output_format = "VisualStudio"
 
+    @property
     def packaging_root(self):
         return Path(f"{self.vscode_platform}/Release")
 

From c91b4379d1621dc375abdc538052db014470f43a Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Tue, 14 Apr 2026 06:01:12 +0300
Subject: [PATCH 14/24] Refuse to run with a x86_64 interpreter

---
 src/briefcase/platforms/windows/__init__.py   | 11 ++++++++
 .../windows/app/create/test_create.py         | 26 +++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/src/briefcase/platforms/windows/__init__.py b/src/briefcase/platforms/windows/__init__.py
index 04003fe529..2ac6cfb41f 100644
--- a/src/briefcase/platforms/windows/__init__.py
+++ b/src/briefcase/platforms/windows/__init__.py
@@ -94,6 +94,17 @@ def vscode_platform(self):
 
     def verify_host(self):
         super().verify_host()
+        if (
+            self.tools.host_arch == "ARM64"
+            and "AMD64" in self.tools.platform.python_compiler()
+        ):
+            raise UnsupportedHostError(
+                "The Python interpreter that is being used to run Briefcase has been "
+                "compiled for x86_64, and is running in emulation mode on ARM64"
+                "hardware. You must use a Python interpreter that has been "
+                "compiled for ARM64."
+            )
+
         if self.tools.host_arch not in ("AMD64", "ARM64"):
             if all(app.external_package_path for app in self.apps.values()):
                 if not self.is_clone:
diff --git a/tests/platforms/windows/app/create/test_create.py b/tests/platforms/windows/app/create/test_create.py
index 32cc356f13..82c51bb0d3 100644
--- a/tests/platforms/windows/app/create/test_create.py
+++ b/tests/platforms/windows/app/create/test_create.py
@@ -1,4 +1,6 @@
+import platform
 import sys
+from unittest.mock import MagicMock
 
 import pytest
 from packaging.version import Version
@@ -82,6 +84,30 @@ def test_unsupported_32bit_python(create_command):
         create_command()
 
 
+def test_verify_windows_cpu_arch(create_command):
+    """Running through x86_64 emulation on Windows ARM64 will raise an error."""
+
+    # Create a Mock object for the platform module
+    create_command.tools.platform = MagicMock(spec_set=platform)
+
+    # Simulate that Mock platform is running on Windows ARM64 with an x86_64 Python interpreter
+    create_command.tools.host_arch = "ARM64"
+    create_command.tools.platform.python_compiler = MagicMock(
+        return_value="MSV v.1950 64 bit (AMD64)"
+    )
+
+    with pytest.raises(
+        UnsupportedHostError,
+        match=(
+            r"The Python interpreter that is being used to run Briefcase has been "
+            r"compiled for x86_64, and is running in emulation mode on ARM64"
+            r"hardware. You must use a Python interpreter that has been "
+            r"compiled for ARM64."
+        ),
+    ):
+        create_command.verify_host()
+
+
 def test_context(create_command, first_app_config):
     context = create_command.output_format_template_context(first_app_config)
     assert sorted(context.keys()) == [

From a2fae660611c318434dfc045b5c4dd49b1c48da6 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Tue, 14 Apr 2026 06:27:45 +0300
Subject: [PATCH 15/24] Fix non-Windows coverage

---
 tests/platforms/windows/app/create/test_create.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/platforms/windows/app/create/test_create.py b/tests/platforms/windows/app/create/test_create.py
index 82c51bb0d3..3dd561e77a 100644
--- a/tests/platforms/windows/app/create/test_create.py
+++ b/tests/platforms/windows/app/create/test_create.py
@@ -91,6 +91,7 @@ def test_verify_windows_cpu_arch(create_command):
     create_command.tools.platform = MagicMock(spec_set=platform)
 
     # Simulate that Mock platform is running on Windows ARM64 with an x86_64 Python interpreter
+    create_command.tools.host_os = "Windows"
     create_command.tools.host_arch = "ARM64"
     create_command.tools.platform.python_compiler = MagicMock(
         return_value="MSV v.1950 64 bit (AMD64)"

From 9a81caa8c516879e193d42bcd6bf5873c8101417 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 12:25:34 +0300
Subject: [PATCH 16/24] Add missing space

---
 src/briefcase/platforms/windows/__init__.py       | 2 +-
 tests/platforms/windows/app/create/test_create.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/briefcase/platforms/windows/__init__.py b/src/briefcase/platforms/windows/__init__.py
index 2ac6cfb41f..ffa6370051 100644
--- a/src/briefcase/platforms/windows/__init__.py
+++ b/src/briefcase/platforms/windows/__init__.py
@@ -100,7 +100,7 @@ def verify_host(self):
         ):
             raise UnsupportedHostError(
                 "The Python interpreter that is being used to run Briefcase has been "
-                "compiled for x86_64, and is running in emulation mode on ARM64"
+                "compiled for x86_64, and is running in emulation mode on ARM64 "
                 "hardware. You must use a Python interpreter that has been "
                 "compiled for ARM64."
             )
diff --git a/tests/platforms/windows/app/create/test_create.py b/tests/platforms/windows/app/create/test_create.py
index 3dd561e77a..61b036e60e 100644
--- a/tests/platforms/windows/app/create/test_create.py
+++ b/tests/platforms/windows/app/create/test_create.py
@@ -101,7 +101,7 @@ def test_verify_windows_cpu_arch(create_command):
         UnsupportedHostError,
         match=(
             r"The Python interpreter that is being used to run Briefcase has been "
-            r"compiled for x86_64, and is running in emulation mode on ARM64"
+            r"compiled for x86_64, and is running in emulation mode on ARM64 "
             r"hardware. You must use a Python interpreter that has been "
             r"compiled for ARM64."
         ),

From bd2e6a9722a2ed970399ff0f6c9b76ad23c986d5 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 12:26:10 +0300
Subject: [PATCH 17/24] Update release note

---
 changes/1887.feature.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/changes/1887.feature.md b/changes/1887.feature.md
index 5371449d65..76117f8715 100644
--- a/changes/1887.feature.md
+++ b/changes/1887.feature.md
@@ -1 +1 @@
-Windows on ARM64 is now supported.
+Briefcase can now build Windows apps for ARM64 devices.

From c66079969507efc2c5394b2d80ae8a8617c236e5 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 13:59:30 +0300
Subject: [PATCH 18/24] Detect ARM64 on older Python versions

---
 src/briefcase/integrations/base.py | 32 +++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/briefcase/integrations/base.py b/src/briefcase/integrations/base.py
index 2b412bf586..b8df49821e 100644
--- a/src/briefcase/integrations/base.py
+++ b/src/briefcase/integrations/base.py
@@ -195,7 +195,7 @@ def __init__(
         self.base_path = Path(base_path)
         self.home_path = Path(os.path.expanduser(home_path or Path.home()))
 
-        self.host_arch = self.platform.machine()
+        self.host_arch = self._get_host_arch()
         self.host_os = self.platform.system()
         # Python is 32bit if its pointers can only address with 32 bits or fewer
         self.is_32bit_python = self.sys.maxsize <= 2**32
@@ -208,6 +208,36 @@ def __init__(
             )
         )
 
+    def _get_host_arch(self) -> str:
+        arch = self.platform.machine()
+        # On Windows with Python < 3.12, ``platform.machine()`` returns the
+        # emulated architecture (e.g. "AMD64") when an x86-64 Python interpreter
+        # is running under ARM64.  ``IsWow64Process2()`` exposes the
+        # native machine type.
+        if (
+            arch == "AMD64"
+            and self.platform.system() == "Windows"
+            and self.sys.version_info < (3, 12)
+            and self.sys.getwindowsversion().build >= 16299  # Windows 10 1709
+        ):
+            import ctypes
+            from ctypes import wintypes
+
+            IMAGE_FILE_MACHINE_ARM64 = 0xAA64
+            kernel32 = ctypes.windll.kernel32
+            process_machine = ctypes.c_ushort(0)
+            native_machine = ctypes.c_ushort(0)
+            if (
+                kernel32.IsWow64Process2(
+                    wintypes.HANDLE(kernel32.GetCurrentProcess()),
+                    ctypes.byref(process_machine),
+                    ctypes.byref(native_machine),
+                )
+                and native_machine.value == IMAGE_FILE_MACHINE_ARM64
+            ):
+                return "ARM64"
+        return arch
+
     @cached_property
     def system_encoding(self) -> str:
         """The character encoding for the system's locale.

From 9eceb52cda7f60e29f38c1acff32495301990106 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 14:50:33 +0300
Subject: [PATCH 19/24] Add a test

---
 src/briefcase/integrations/base.py        |  4 ++--
 tests/integrations/base/test_ToolCache.py | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/briefcase/integrations/base.py b/src/briefcase/integrations/base.py
index b8df49821e..753ff9f817 100644
--- a/src/briefcase/integrations/base.py
+++ b/src/briefcase/integrations/base.py
@@ -195,8 +195,8 @@ def __init__(
         self.base_path = Path(base_path)
         self.home_path = Path(os.path.expanduser(home_path or Path.home()))
 
-        self.host_arch = self._get_host_arch()
         self.host_os = self.platform.system()
+        self.host_arch = self._get_host_arch()
         # Python is 32bit if its pointers can only address with 32 bits or fewer
         self.is_32bit_python = self.sys.maxsize <= 2**32
 
@@ -216,7 +216,7 @@ def _get_host_arch(self) -> str:
         # native machine type.
         if (
             arch == "AMD64"
-            and self.platform.system() == "Windows"
+            and self.host_os == "Windows"
             and self.sys.version_info < (3, 12)
             and self.sys.getwindowsversion().build >= 16299  # Windows 10 1709
         ):
diff --git a/tests/integrations/base/test_ToolCache.py b/tests/integrations/base/test_ToolCache.py
index 07f4fb3cba..aef45cd60c 100644
--- a/tests/integrations/base/test_ToolCache.py
+++ b/tests/integrations/base/test_ToolCache.py
@@ -109,6 +109,29 @@ def test_host_arch_and_os(simple_tools):
     assert simple_tools.host_os == platform.system()
 
 
+def test_get_host_arch_windows_arm64(dummy_console, monkeypatch, tmp_path):
+    """ARM64 is detected on Windows with a pre-3.12 Python x86_64 interpreter."""
+    mock_ctypes = MagicMock()
+    mock_ctypes.c_ushort.return_value.value = 0xAA64  # IMAGE_FILE_MACHINE_ARM64
+
+    mock_platform = MagicMock()
+    mock_platform.machine.return_value = "AMD64"
+    mock_platform.system.return_value = "Windows"
+
+    mock_sys = MagicMock()
+    mock_sys.version_info = (3, 11, 0)
+    mock_sys.getwindowsversion.return_value.build = 16299
+    mock_sys.maxsize = 2**64
+
+    monkeypatch.setattr(ToolCache, "platform", mock_platform)
+    monkeypatch.setattr(ToolCache, "sys", mock_sys)
+    monkeypatch.setitem(sys.modules, "ctypes", mock_ctypes)
+
+    tools = ToolCache(console=dummy_console, base_path=tmp_path)
+
+    assert tools.host_arch == "ARM64"
+
+
 def test_base_path_is_path(dummy_console, simple_tools):
     """Base path is always a Path."""
     # The BaseCommand tests have much more extensive tests for this path.

From f435a2d94cf28e837f5f36a0920a2c5f4d19e054 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 14:55:36 +0300
Subject: [PATCH 20/24] Update Visual Studio docs

---
 docs/en/reference/platforms/windows/visualstudio.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/docs/en/reference/platforms/windows/visualstudio.md b/docs/en/reference/platforms/windows/visualstudio.md
index 2d92bf0ba6..3ec4f4908d 100644
--- a/docs/en/reference/platforms/windows/visualstudio.md
+++ b/docs/en/reference/platforms/windows/visualstudio.md
@@ -60,7 +60,7 @@ All Windows apps, regardless of output format, use the same icon formats, have t
 
 ## Pre-requisites
 
-Building the Visual Studio project requires that you install Visual Studio 2022 or later. Visual Studio 2022 Community Edition [can be downloaded for free from Microsoft](https://visualstudio.microsoft.com/vs/community/). You can also use the Professional or Enterprise versions if you have them.
+Building the Visual Studio project requires that you install Visual Studio. Visual Studio Community Edition [can be downloaded for free from Microsoft](https://visualstudio.microsoft.com/vs/community/). You can also use the Professional or Enterprise versions if you have them.
 
 Briefcase will auto-detect the location of your Visual Studio installation, provided one of the following three things are true:
 
@@ -75,6 +75,7 @@ When you install Visual Studio, there are many optional components. You should e
 - Desktop Development with C++
   - All default packages
   - C++/CLI support for v143 build tools
+  - MSVS v143 VS 2022 C++ ARM64/x64 build tools
 
 ## Application configuration
 

From a483bcb155e0df0085a0b94e112e574a07517f1a Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 15:36:37 +0300
Subject: [PATCH 21/24] Add additional test for more coverage

---
 tests/integrations/base/test_ToolCache.py | 24 +++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/tests/integrations/base/test_ToolCache.py b/tests/integrations/base/test_ToolCache.py
index aef45cd60c..5195b6a225 100644
--- a/tests/integrations/base/test_ToolCache.py
+++ b/tests/integrations/base/test_ToolCache.py
@@ -132,6 +132,30 @@ def test_get_host_arch_windows_arm64(dummy_console, monkeypatch, tmp_path):
     assert tools.host_arch == "ARM64"
 
 
+def test_get_host_arch_windows_not_arm64(dummy_console, monkeypatch, tmp_path):
+    """AMD64 is returned when IsWow64Process2 reports the native machine is not
+    ARM64."""
+    mock_ctypes = MagicMock()
+    mock_ctypes.windll.kernel32.IsWow64Process2.return_value = 0
+
+    mock_platform = MagicMock()
+    mock_platform.machine.return_value = "AMD64"
+    mock_platform.system.return_value = "Windows"
+
+    mock_sys = MagicMock()
+    mock_sys.version_info = (3, 11, 0)
+    mock_sys.getwindowsversion.return_value.build = 16299
+    mock_sys.maxsize = 2**64
+
+    monkeypatch.setattr(ToolCache, "platform", mock_platform)
+    monkeypatch.setattr(ToolCache, "sys", mock_sys)
+    monkeypatch.setitem(sys.modules, "ctypes", mock_ctypes)
+
+    tools = ToolCache(console=dummy_console, base_path=tmp_path)
+
+    assert tools.host_arch == "AMD64"
+
+
 def test_base_path_is_path(dummy_console, simple_tools):
     """Base path is always a Path."""
     # The BaseCommand tests have much more extensive tests for this path.

From 05b5ce2c90c899327743983906bb27482926edcb Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 15:40:41 +0300
Subject: [PATCH 22/24] Fix spelling lint

---
 docs/en/reference/platforms/windows/visualstudio.md | 2 +-
 docs/spelling_wordlist                              | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/docs/en/reference/platforms/windows/visualstudio.md b/docs/en/reference/platforms/windows/visualstudio.md
index 3ec4f4908d..29cf43c432 100644
--- a/docs/en/reference/platforms/windows/visualstudio.md
+++ b/docs/en/reference/platforms/windows/visualstudio.md
@@ -75,7 +75,7 @@ When you install Visual Studio, there are many optional components. You should e
 - Desktop Development with C++
   - All default packages
   - C++/CLI support for v143 build tools
-  - MSVS v143 VS 2022 C++ ARM64/x64 build tools
+  - MSVC v143 VS 2022 C++ ARM64/x64 build tools
 
 ## Application configuration
 
diff --git a/docs/spelling_wordlist b/docs/spelling_wordlist
index 8935009eaf..3c4387b701 100644
--- a/docs/spelling_wordlist
+++ b/docs/spelling_wordlist
@@ -237,3 +237,4 @@ Xauth
 Xcode
 Xr
 Xs
+MSVC

From 371794a97a5ac035d20c9692873105a33b9088a0 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Thu, 16 Apr 2026 16:14:12 +0300
Subject: [PATCH 23/24] Add a test for Python 3.12+

---
 tests/integrations/base/test_ToolCache.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tests/integrations/base/test_ToolCache.py b/tests/integrations/base/test_ToolCache.py
index 5195b6a225..feec097739 100644
--- a/tests/integrations/base/test_ToolCache.py
+++ b/tests/integrations/base/test_ToolCache.py
@@ -156,6 +156,25 @@ def test_get_host_arch_windows_not_arm64(dummy_console, monkeypatch, tmp_path):
     assert tools.host_arch == "AMD64"
 
 
+def test_get_host_arch_windows_python312(dummy_console, monkeypatch, tmp_path):
+    """On Python 3.12+, IsWow64Process2 is not called; platform.machine() is used
+    directly."""
+    mock_platform = MagicMock()
+    mock_platform.machine.return_value = "AMD64"
+    mock_platform.system.return_value = "Windows"
+
+    mock_sys = MagicMock()
+    mock_sys.version_info = (3, 12, 0)
+    mock_sys.maxsize = 2**64
+
+    monkeypatch.setattr(ToolCache, "platform", mock_platform)
+    monkeypatch.setattr(ToolCache, "sys", mock_sys)
+
+    tools = ToolCache(console=dummy_console, base_path=tmp_path)
+
+    assert tools.host_arch == "AMD64"
+
+
 def test_base_path_is_path(dummy_console, simple_tools):
     """Base path is always a Path."""
     # The BaseCommand tests have much more extensive tests for this path.

From 9149fdd28e1eb7b4c3da73e2f5616e05cf86c397 Mon Sep 17 00:00:00 2001
From: Abdo <abdo@abdnh.net>
Date: Fri, 17 Apr 2026 17:33:57 +0300
Subject: [PATCH 24/24] Update message about required VSCode components

---
 src/briefcase/integrations/visualstudio.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/briefcase/integrations/visualstudio.py b/src/briefcase/integrations/visualstudio.py
index ace35185a4..e42d13f961 100644
--- a/src/briefcase/integrations/visualstudio.py
+++ b/src/briefcase/integrations/visualstudio.py
@@ -18,7 +18,7 @@ class VisualStudio(Tool):
       - Default packages
     * Desktop Development with C++
       - Default packages; plus
-      - C++/CLI support for v143 build tools
+      - MSVC v143 VS 2022 C++ ARM64/x64 build tools
 """
 
     def __init__(