diff --git a/src/commands/install.ts b/src/commands/install.ts
index b4c015e..0441d99 100644
--- a/src/commands/install.ts
+++ b/src/commands/install.ts
@@ -19,6 +19,9 @@ interface InstallSourceInfo {
   localRoot?: string;
 }
 
+const WINDOWS_DRIVE_PATH = /^[a-zA-Z]:[\\/]/;
+const WINDOWS_MSYS_PATH = /^\/([a-zA-Z])([\\/].*)$/;
+
 /**
  * Check if source is a local path
  */
@@ -27,7 +30,9 @@ function isLocalPath(source: string): boolean {
     source.startsWith('/') ||
     source.startsWith('./') ||
     source.startsWith('../') ||
-    source.startsWith('~/')
+    source.startsWith('~/') ||
+    source.startsWith('~\\') ||
+    WINDOWS_DRIVE_PATH.test(source)
   );
 }
 
@@ -59,9 +64,18 @@ function getRepoName(repoUrl: string): string | null {
  * Expand ~ to home directory
  */
 function expandPath(source: string): string {
-  if (source.startsWith('~/')) {
+  if (source.startsWith('~/') || source.startsWith('~\\')) {
     return join(homedir(), source.slice(2));
   }
+
+  if (process.platform === 'win32') {
+    const msysMatch = source.match(WINDOWS_MSYS_PATH);
+    if (msysMatch) {
+      const [, drive, rest] = msysMatch;
+      return resolve(`${drive.toUpperCase()}:${rest}`);
+    }
+  }
+
   return resolve(source);
 }
 
@@ -491,7 +505,7 @@ function buildMetadataFromSource(
     return buildLocalMetadata(sourceInfo, skillDir);
   }
   const subpath = relative(repoDir, skillDir);
-  const normalizedSubpath = subpath === '' ? '' : subpath;
+  const normalizedSubpath = subpath === '' ? '' : subpath.split(sep).join('/');
   return buildGitMetadata(sourceInfo, normalizedSubpath);
 }
 
diff --git a/src/commands/sync.ts b/src/commands/sync.ts
index d8746eb..9478723 100644
--- a/src/commands/sync.ts
+++ b/src/commands/sync.ts
@@ -1,5 +1,6 @@
 import { existsSync, readFileSync, writeFileSync, mkdirSync } from 'fs';
-import { dirname, basename } from 'path';
+import { dirname, basename, resolve, join } from 'path';
+import { homedir } from 'os';
 import chalk from 'chalk';
 import { checkbox } from '@inquirer/prompts';
 import { ExitPromptError } from '@inquirer/core';
@@ -12,11 +13,19 @@ export interface SyncOptions {
   output?: string;
 }
 
+function expandOutputPath(outputPath: string): string {
+  if (outputPath.startsWith('~/') || outputPath.startsWith('~\\')) {
+    return resolve(join(homedir(), outputPath.slice(2)));
+  }
+
+  return resolve(outputPath);
+}
+
 /**
  * Sync installed skills to a markdown file
  */
 export async function syncAgentsMd(options: SyncOptions = {}): Promise<void> {
-  const outputPath = options.output || 'AGENTS.md';
+  const outputPath = expandOutputPath(options.output || 'AGENTS.md');
   const outputName = basename(outputPath);
 
   // Validate output file is markdown
diff --git a/tests/commands/install.test.ts b/tests/commands/install.test.ts
index f89d811..67e0179 100644
--- a/tests/commands/install.test.ts
+++ b/tests/commands/install.test.ts
@@ -10,13 +10,16 @@ import { extractYamlField, hasValidFrontmatter } from '../../src/utils/yaml.js';
 
 describe('install.ts helper functions', () => {
   describe('isLocalPath detection', () => {
+    const windowsDrivePath = /^[a-zA-Z]:[\\/]/;
     // Replicate the logic from isLocalPath()
     const isLocalPath = (source: string): boolean => {
       return (
         source.startsWith('/') ||
         source.startsWith('./') ||
         source.startsWith('../') ||
-        source.startsWith('~/')
+        source.startsWith('~/') ||
+        source.startsWith('~\\') ||
+        windowsDrivePath.test(source)
       );
     };
 
@@ -40,6 +43,12 @@ describe('install.ts helper functions', () => {
       expect(isLocalPath('~/.claude/skills')).toBe(true);
     });
 
+    it('should detect Windows local path formats', () => {
+      expect(isLocalPath('~\\skills\\my-skill')).toBe(true);
+      expect(isLocalPath('C:/Users/dev/skills/my-skill')).toBe(true);
+      expect(isLocalPath('D:\\Users\\dev\\skills\\my-skill')).toBe(true);
+    });
+
     it('should NOT detect GitHub shorthand as local path', () => {
       expect(isLocalPath('owner/repo')).toBe(false);
       expect(isLocalPath('anthropics/skills')).toBe(false);
@@ -108,11 +117,21 @@ describe('install.ts helper functions', () => {
   });
 
   describe('expandPath tilde expansion', () => {
+    const windowsMsysPath = /^\/([a-zA-Z])([\\/].*)$/;
     // Replicate the logic from expandPath()
-    const expandPath = (source: string): string => {
-      if (source.startsWith('~/')) {
+    const expandPath = (source: string, platform: NodeJS.Platform = process.platform): string => {
+      if (source.startsWith('~/') || source.startsWith('~\\')) {
         return join(homedir(), source.slice(2));
       }
+
+      if (platform === 'win32') {
+        const msysMatch = source.match(windowsMsysPath);
+        if (msysMatch) {
+          const [, drive, rest] = msysMatch;
+          return resolve(`${drive.toUpperCase()}:${rest}`);
+        }
+      }
+
       return resolve(source);
     };
 
@@ -126,6 +145,17 @@ describe('install.ts helper functions', () => {
       expect(expanded).toBe(join(homedir(), '.claude/skills'));
     });
 
+    it('should expand ~\\ on Windows-style inputs', () => {
+      const expanded = expandPath('~\\skills\\demo');
+      expect(expanded).toBe(join(homedir(), 'skills\\demo'));
+    });
+
+    it('should map /c/... paths on Windows', () => {
+      const expanded = expandPath('/c/Users/dev/skills/demo', 'win32');
+      expect(expanded).toContain('C:');
+      expect(expanded.toLowerCase()).toContain('users');
+    });
+
     it('should resolve relative paths', () => {
       const expanded = expandPath('./relative');
       expect(expanded).toBe(resolve('./relative'));
@@ -243,6 +273,16 @@ describe('install.ts helper functions', () => {
       }
     });
   });
+
+  describe('metadata subpath normalization', () => {
+    const normalizeSubpath = (subpath: string, pathSep: string): string =>
+      subpath === '' ? '' : subpath.split(pathSep).join('/');
+
+    it('normalizes Windows separators in subpath metadata', () => {
+      expect(normalizeSubpath('plugins\\ui-design\\skills\\accessibility-compliance', '\\'))
+        .toBe('plugins/ui-design/skills/accessibility-compliance');
+    });
+  });
 });
 
 describe('GitHub shorthand parsing', () => {
diff --git a/tests/commands/sync.test.ts b/tests/commands/sync.test.ts
index a6ebc70..e7c6f1e 100644
--- a/tests/commands/sync.test.ts
+++ b/tests/commands/sync.test.ts
@@ -2,6 +2,7 @@ import { describe, it, expect, beforeEach, afterEach } from 'vitest';
 import { mkdirSync, writeFileSync, readFileSync, rmSync, existsSync } from 'fs';
 import { join, dirname, basename } from 'path';
 import { tmpdir } from 'os';
+import { homedir } from 'os';
 
 // Test the sync utility functions directly
 import {
@@ -179,6 +180,13 @@ describe('sync --output flag logic', () => {
   });
 
   describe('output path validation', () => {
+    const expandOutputPath = (outputPath: string): string => {
+      if (outputPath.startsWith('~/') || outputPath.startsWith('~\\')) {
+        return join(homedir(), outputPath.slice(2));
+      }
+      return outputPath;
+    };
+
     it('should accept .md files', () => {
       const validPaths = [
         'AGENTS.md',
@@ -204,6 +212,13 @@ describe('sync --output flag logic', () => {
         expect(path.endsWith('.md')).toBe(false);
       }
     });
+
+    it('should expand tilde paths for output destination', () => {
+      expect(expandOutputPath('~/.config/opencode/AGENTS.md'))
+        .toBe(join(homedir(), '.config/opencode/AGENTS.md'));
+      expect(expandOutputPath('~\\.config\\opencode\\AGENTS.md'))
+        .toBe(join(homedir(), '.config\\opencode\\AGENTS.md'));
+    });
   });
 
   describe('auto-create file behavior', () => {