diff --git a/cmd/app.go b/cmd/app.go
index 39738bc..c55a8a7 100644
--- a/cmd/app.go
+++ b/cmd/app.go
@@ -2,10 +2,24 @@ package cmd
 
 import (
 	"fmt"
+	"io"
 
 	"github.com/urfave/cli/v2"
 )
 
+func init() {
+	// Override the default HelpPrinter to write directly to the provided
+	// io.Writer using fmt.Fprint.  This avoids any OS-specific pager or
+	// man-page lookup and ensures --help works identically on Windows,
+	// macOS, and Linux.
+	// HelpPrinterCustom renders the help template directly into w via
+	// text/template.Execute — no external pager, man-page, or shell command
+	// is invoked, which is what makes this safe on Windows/PowerShell.
+	cli.HelpPrinter = func(w io.Writer, templ string, data interface{}) {
+		cli.HelpPrinterCustom(w, templ, data, nil)
+	}
+}
+
 // Handlers contains injected command actions so CLI wiring can live outside main.
 type Handlers struct {
 	RunReviewSimple       cli.ActionFunc
diff --git a/internal/appcore/review_runtime.go b/internal/appcore/review_runtime.go
index c18ce75..127800c 100644
--- a/internal/appcore/review_runtime.go
+++ b/internal/appcore/review_runtime.go
@@ -170,7 +170,7 @@ func runReviewWithOptions(opts reviewopts.Options) error {
 			return fmt.Errorf("failed to collect diff for vouch: %w", diffErr)
 		}
 		if len(diffContent) == 0 {
-			return fmt.Errorf("no diff content to vouch for")
+			return fmt.Errorf("%s", noDiffMessage(opts.DiffSource))
 		}
 		parsedFiles, parseErr := parseDiffToFiles(diffContent)
 		if parseErr != nil {
@@ -271,7 +271,7 @@ func runReviewWithOptions(opts reviewopts.Options) error {
 	}
 
 	if len(diffContent) == 0 {
-		return fmt.Errorf("no diff content collected")
+		return fmt.Errorf("%s", noDiffMessage(opts.DiffSource))
 	}
 
 	var fakeBaseFiles []reviewmodel.DiffReviewFileResult
@@ -1368,6 +1368,25 @@ func collectDiffWithOptions(opts reviewopts.Options) ([]byte, error) {
 	}
 }
 
+// noDiffMessage returns a beginner-friendly error string tailored to the
+// diff source that produced no content.
+func noDiffMessage(diffSource string) string {
+	switch diffSource {
+	case "staged":
+		return "No staged changes found. Please stage your files using `git add <file>` before running a review."
+	case "working":
+		return "No working-tree changes found. Make some edits before running a review."
+	case "commit":
+		return "The specified commit(s) produced an empty diff. Verify the commit reference and try again."
+	case "range":
+		return "The specified range produced an empty diff. Verify the range and try again."
+	case "file":
+		return "The provided diff file is empty. Provide a non-empty diff file."
+	default:
+		return "No diff content collected."
+	}
+}
+
 // runCommitAndMaybePush commits the staged changes and optionally pushes with safety checks.
 func runCommitAndMaybePush(message string, push bool, verbose bool) error {
 	msg := strings.TrimSpace(message)