diff --git a/src/api/services/validation-service.ts b/src/api/services/validation-service.ts
index 0973ca13..e9b830ce 100644
--- a/src/api/services/validation-service.ts
+++ b/src/api/services/validation-service.ts
@@ -5,7 +5,7 @@
  * Extracted from api-command.ts for reuse and testability.
  */
 
-import { isReservedName } from '../../config/reserved-names';
+import { isReservedName, isWindowsReservedName } from '../../config/reserved-names';
 
 /**
  * Validate API profile name
@@ -24,6 +24,9 @@ export function validateApiName(name: string): string | null {
   if (isReservedName(name)) {
     return `'${name}' is a reserved name`;
   }
+  if (isWindowsReservedName(name)) {
+    return `'${name}' is a Windows reserved device name and cannot be used`;
+  }
   return null;
 }
 
diff --git a/src/cliproxy/services/binary-service.ts b/src/cliproxy/services/binary-service.ts
index c044aca4..ff769e65 100644
--- a/src/cliproxy/services/binary-service.ts
+++ b/src/cliproxy/services/binary-service.ts
@@ -84,10 +84,10 @@ export async function checkLatestVersion(): Promise<LatestVersionResult> {
 }
 
 /**
- * Validate version format
+ * Validate version format (supports X.Y.Z or X.Y.Z-N suffix)
  */
 export function isValidVersionFormat(version: string): boolean {
-  return /^\d+\.\d+\.\d+$/.test(version);
+  return /^\d+\.\d+\.\d+(-\d+)?$/.test(version);
 }
 
 /**
diff --git a/src/cliproxy/services/variant-service.ts b/src/cliproxy/services/variant-service.ts
index 58e4e05d..41a5dcfb 100644
--- a/src/cliproxy/services/variant-service.ts
+++ b/src/cliproxy/services/variant-service.ts
@@ -9,7 +9,7 @@ import * as os from 'os';
 import * as path from 'path';
 import { CLIProxyProfileName } from '../../auth/profile-detector';
 import { CLIProxyProvider } from '../types';
-import { isReservedName } from '../../config/reserved-names';
+import { isReservedName, isWindowsReservedName } from '../../config/reserved-names';
 import { isUnifiedMode } from '../../config/unified-config-loader';
 import { deleteConfigForPort } from '../config-generator';
 import { deleteSessionLockForPort } from '../session-tracker';
@@ -58,6 +58,9 @@ export function validateProfileName(name: string): string | null {
   if (isReservedName(name)) {
     return `'${name}' is a reserved name`;
   }
+  if (isWindowsReservedName(name)) {
+    return `'${name}' is a Windows reserved device name and cannot be used`;
+  }
   return null;
 }
 
diff --git a/src/commands/cliproxy-command.ts b/src/commands/cliproxy-command.ts
index e0e93e35..bce8a3b9 100644
--- a/src/commands/cliproxy-command.ts
+++ b/src/commands/cliproxy-command.ts
@@ -619,13 +619,15 @@ export async function handleCliproxyCommand(args: string[]): Promise<void> {
 
   const installIdx = args.indexOf('--install');
   if (installIdx !== -1) {
-    const version = args[installIdx + 1];
+    let version = args[installIdx + 1];
     if (!version || version.startsWith('-')) {
       console.error(fail('Missing version argument for --install'));
       console.error('    Usage: ccs cliproxy --install <version>');
-      console.error('    Example: ccs cliproxy --install 6.5.53');
+      console.error('    Example: ccs cliproxy --install 6.6.80-0');
       process.exit(1);
     }
+    // Strip leading 'v' prefix and whitespace (user may type " v6.6.80-0 ")
+    version = version.trim().replace(/^v/, '');
     await handleInstallVersion(version, verbose);
     return;
   }
diff --git a/src/config/reserved-names.ts b/src/config/reserved-names.ts
index 25262265..7e53f4c3 100644
--- a/src/config/reserved-names.ts
+++ b/src/config/reserved-names.ts
@@ -19,6 +19,35 @@ export const RESERVED_PROFILE_NAMES = [
 
 export type ReservedProfileName = (typeof RESERVED_PROFILE_NAMES)[number];
 
+/**
+ * Windows reserved device names - cannot be used as filenames on Windows.
+ * Case-insensitive on Windows filesystem.
+ */
+export const WINDOWS_RESERVED_NAMES = [
+  'CON',
+  'PRN',
+  'AUX',
+  'NUL',
+  'COM1',
+  'COM2',
+  'COM3',
+  'COM4',
+  'COM5',
+  'COM6',
+  'COM7',
+  'COM8',
+  'COM9',
+  'LPT1',
+  'LPT2',
+  'LPT3',
+  'LPT4',
+  'LPT5',
+  'LPT6',
+  'LPT7',
+  'LPT8',
+  'LPT9',
+] as const;
+
 /**
  * Check if a name is reserved and cannot be used for user profiles.
  * @param name - The profile name to check
@@ -28,6 +57,18 @@ export function isReservedName(name: string): boolean {
   return RESERVED_PROFILE_NAMES.includes(name.toLowerCase() as ReservedProfileName);
 }
 
+/**
+ * Check if a name is a Windows reserved device name.
+ * These cause filesystem errors on Windows systems.
+ * @param name - The name to check
+ * @returns true if the name is a Windows reserved name
+ */
+export function isWindowsReservedName(name: string): boolean {
+  return WINDOWS_RESERVED_NAMES.includes(
+    name.toUpperCase() as (typeof WINDOWS_RESERVED_NAMES)[number]
+  );
+}
+
 /**
  * Validate a profile name and throw if reserved.
  * @param name - The profile name to validate