[BUG] Missing HCS services: vfpext — persists after Hyper-V enable, DISM, SFC, and cache clear on Windows 11 Pro

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Clicking the Cowork tab in Claude Desktop shows "Missing HCS services: vfpext". The tab remains disabled and Cowork cannot be used.

Verification via PowerShell confirmed the driver file is genuinely absent:

Test-Path C:\Windows\System32\drivers\vfpext.sys
Result: False


### What Should Happen?

Cowork tab should be accessible and functional on Windows 11 Pro with a paid Pro subscription and Hyper-V fully enabled.



### Error Messages/Logs

```shell
Cowork tab shows "Missing HCS services: vfpext" and remains disabled. The vfpext.sys driver file is absent from `C:\Windows\System32\drivers` and no standard repair path restores it.

Steps to Reproduce

1. Enabled Hyper-V, Virtual Machine Platform, and Containers via Turn Windows features on or off → restarted
2. Ran DISM /Online /Cleanup-Image /RestoreHealth (elevated) — completed successfully, no effect
3. Ran sfc /scannow (elevated) — completed, no effect
4. Cleared Claude Desktop cache via Help → Troubleshoot
5. Fully uninstalled and reinstalled Claude Desktop from claude.com/download
6. Confirmed Test-Path C:\Windows\System32\drivers\vfpext.sys returns False at every stage

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

1.25927.0.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

This matches the pattern reported in multiple existing issues. As noted in #83132, the driver appears to be missing even from clean official Windows 11 ISO images for certain configurations, suggesting this may be a detection logic issue on Cowork's side rather than a user-resolvable Windows problem. A fix at the application level would be greatly appreciated.