diff --git a/src/coreclr/debug/daccess/stdafx.h b/src/coreclr/debug/daccess/stdafx.h
index bff6a4f660379b..e439a01b9fe7e6 100644
--- a/src/coreclr/debug/daccess/stdafx.h
+++ b/src/coreclr/debug/daccess/stdafx.h
@@ -18,8 +18,6 @@
 // and there's no reason why DAC should be forbidden from using it.
 #define DO_NOT_DISABLE_RAND
 
-#define USE_COM_CONTEXT_DEF
-
 #include <stddef.h>
 #include <stdint.h>
 #include <windows.h>
diff --git a/src/coreclr/debug/ee/stdafx.h b/src/coreclr/debug/ee/stdafx.h
index 4a07384047d0a7..5fecaecb9bc86d 100644
--- a/src/coreclr/debug/ee/stdafx.h
+++ b/src/coreclr/debug/ee/stdafx.h
@@ -7,8 +7,6 @@
 //
 //*****************************************************************************
 
-#define USE_COM_CONTEXT_DEF
-
 #include <stdint.h>
 #include <wchar.h>
 #include <stdio.h>
diff --git a/src/coreclr/md/ceefilegen/stdafx.h b/src/coreclr/md/ceefilegen/stdafx.h
index 4026a47f14107d..db15968905ac15 100644
--- a/src/coreclr/md/ceefilegen/stdafx.h
+++ b/src/coreclr/md/ceefilegen/stdafx.h
@@ -8,7 +8,6 @@
 // Common include file for utility code.
 //*****************************************************************************
 
-#define _CRT_DEPENDENCY_  //this code depends on the crt file functions
 #include <crtwrap.h>
 #include <string.h>
 #include <limits.h>
diff --git a/src/coreclr/unwinder/stdafx.h b/src/coreclr/unwinder/stdafx.h
index 8decdc68562bd4..4b9c1de9e5a6d8 100644
--- a/src/coreclr/unwinder/stdafx.h
+++ b/src/coreclr/unwinder/stdafx.h
@@ -8,8 +8,6 @@
 // and there's no reason why DAC should be forbidden from using it.
 #define DO_NOT_DISABLE_RAND
 
-#define USE_COM_CONTEXT_DEF
-
 #include <common.h>
 
 #include <debugger.h>
diff --git a/src/coreclr/vm/common.h b/src/coreclr/vm/common.h
index 756ef7e0817fbb..54c17e3594bb3a 100644
--- a/src/coreclr/vm/common.h
+++ b/src/coreclr/vm/common.h
@@ -14,45 +14,10 @@
 #define COMMON_TURNED_FPO_ON 1
 #endif
 
-#define USE_COM_CONTEXT_DEF
-
 #if defined(_DEBUG)
 #define DEBUG_REGDISPLAY
 #endif
 
-#ifdef _MSC_VER
-
-    // These don't seem useful, so turning them off is no big deal
-#pragma warning(disable:4201)   // nameless struct/union
-#pragma warning(disable:4512)   // can't generate assignment constructor
-#pragma warning(disable:4211)   // nonstandard extension used (char name[0] in structs)
-#pragma warning(disable:4268)   // 'const' static/global data initialized with compiler generated default constructor fills the object with zeros
-#pragma warning(disable:4238)   // nonstandard extension used : class rvalue used as lvalue
-#pragma warning(disable:4291)   // no matching operator delete found
-#pragma warning(disable:4345)   // behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized
-
-    // Depending on the code base, you may want to not disable these
-#pragma warning(disable:4245)   // assigning signed / unsigned
-#pragma warning(disable:4127)   // conditional expression is constant
-#pragma warning(disable:4100)   // unreferenced formal parameter
-
-#pragma warning(1:4189)   // local variable initialized but not used
-
-#ifndef DEBUG
-#pragma warning(disable:4505)   // unreferenced local function has been removed
-#pragma warning(disable:4313)   // 'format specifier' in format string conflicts with argument %d of type 'type'
-#endif // !DEBUG
-
-    // CONSIDER put these back in
-#pragma warning(disable:4063)   // bad switch value for enum (only in Disasm.cpp)
-#pragma warning(disable:4710)   // function not inlined
-#pragma warning(disable:4527)   // user-defined destructor required
-#pragma warning(disable:4513)   // destructor could not be generated
-#endif // _MSC_VER
-
-#define _CRT_DEPENDENCY_   //this code depends on the crt file functions
-
-
 #include <stdint.h>
 #include <stddef.h>
 #include <winwrap.h>
diff --git a/src/coreclr/vm/gchelpers.cpp b/src/coreclr/vm/gchelpers.cpp
index 7f9ab029d4c6f8..c961814b4966ac 100644
--- a/src/coreclr/vm/gchelpers.cpp
+++ b/src/coreclr/vm/gchelpers.cpp
@@ -1252,7 +1252,8 @@ OBJECTREF AllocateObject(MethodTable *pMT
         if (pMT == g_pBaseCOMObject)
             COMPlusThrow(kInvalidComObjectException, IDS_EE_NO_BACKING_CLASS_FACTORY);
 
-        oref = OBJECTREF_TO_UNCHECKED_OBJECTREF(AllocateComObject_ForManaged(pMT));
+        OBJECTREF obj = AllocateComObject_ForManaged(pMT);
+        oref = OBJECTREF_TO_UNCHECKED_OBJECTREF(obj);
     }
 #endif // FEATURE_COMINTEROP_UNMANAGED_ACTIVATION
 #else  // FEATURE_COMINTEROP
diff --git a/src/coreclr/vm/olevariant.cpp b/src/coreclr/vm/olevariant.cpp
index 90e847f3135c7b..c80e05d81bb6a7 100644
--- a/src/coreclr/vm/olevariant.cpp
+++ b/src/coreclr/vm/olevariant.cpp
@@ -2513,9 +2513,13 @@ BASEARRAYREF OleVariant::ExtractWrappedObjectsFromArray(BASEARRAYREF *pArray)
             for (; pSrc < pSrcEnd; pSrc++, pDest++)
             {
                 if (*pSrc != NULL)
-                    memcpyNoGCRefs(pDest, &(*pSrc)->GetWrappedObject(), sizeof(DECIMAL));
+                {
+                    *pDest = (*pSrc)->GetWrappedObject();
+                }
                 else
-                    memset(pDest, 0, sizeof(DECIMAL));
+                {
+                    *pDest = DECIMAL{};
+                }
             }
         }
         else if (hndWrapperType == TypeHandle(CoreLibBinder::GetClass(CLASS__BSTR_WRAPPER)))