Cowork stopped working on Windows 11 Home after working fine yesterday — vmms unavailable, reinstall x3 did not resolve

[jjhong01-sys]

Preflight Checklist

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

What's Wrong?

What's Wrong?

Claude Cowork worked normally until yesterday on Windows 11 Home. Today, with no intentional system changes, Cowork stopped working (tab/execution not available). Reinstalling Claude Desktop 3 times, running DISM/SFC repair, and enabling Virtual Machine Platform did not resolve the issue.

Environment

• OS: Windows 11 Home, build 10.0.26200
• Architecture: x64
• Disk: 779.6 GB free
• Memory: 31.9 GB

Steps taken

1. Cowork Readiness Check: all PASS except Virtual Machine Platform (initially FAIL, missing services: vfpext)
2. Enabled Virtual Machine Platform via Enable-WindowsOptionalFeature -Online -FeatureName VirtualMachinePlatform -NoRestart → succeeded, rebooted
3. Get-Service CoworkVMService → Running
4. Get-Service vmcompute → Running
5. Get-Service vmms → Not found
6. Get-WindowsOptionalFeature -Online -FeatureName *Hyper-V* → empty result
7. Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All → error: unknown feature name
8. DISM /Online /Cleanup-Image /RestoreHealth → completed
9. sfc /scannow → completed
10. Rebooted, re-checked Hyper-V feature → still empty result
11. Confirmed edition via (Get-CimInstance Win32_OperatingSystem).Caption → Windows 11 Home
12. Fully uninstalled and reinstalled Claude Desktop — 3 times, same result each time

Expected behavior

Cowork should either continue working as it did yesterday, or the app should clearly indicate what changed and why it no longer works on this same Windows Home configuration.

Actual behavior

Cowork tab/execution unavailable. No clear error indicating root cause.

Notes

This matches the pattern in #27384 — Windows Home config that worked previously, then regressed, with local troubleshooting (including full reinstalls) unable to resolve it. Suspect this is an app-side regression rather than a system configuration issue.

What Should Happen?

--

Error Messages/Logs

--

Steps to Reproduce

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Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

--

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

No response

[paperbag27]

+1, same root cause here on Windows 11 Home
Confirms this is a Windows 11 Home limitation, not an app-side regression or driver bug.

Diagnostics:

vfpext.sys — not present in C:\Windows\System32\drivers
sc query vfpext — "The specified service does not exist as an installed service"
dism /online /get-featureinfo /featurename:Microsoft-Hyper-V — Error 0x800f080c, "Feature name Microsoft-Hyper-V is unknown"
winver — Windows 11 Home confirmed

This matches your finding that Get-WindowsOptionalFeature -Online -FeatureName Hyper-V returns empty — Hyper-V genuinely isn't in the Home edition image, so vmms/vfpext can never register no matter how many times you enable Virtual Machine Platform or reinstall.
Given that, I'd guess Cowork's Home-edition readiness check may have been passing previously through a different (non-Hyper-V) code path, and a recent update tightened the requirement to needing full Hyper-V — which Home can't ever satisfy. If so, the fix isn't a repair on our end, it's either restoring a non-Hyper-V sandbox path for Home, or updating the readiness check to fail clearly and explain the edition limitation instead of silently breaking.

[wanshan10x10]

Same issue here on Windows 10 Home, build 10.0.26200. Cowork worked fine for a couple of months, then the tab disappeared last week with no changes on my end. Confirmed via PowerShell:

CoworkVMService, vmcompute, hns — all Running
vmms — not found (expected on Home, but this wasn't a problem before)
Tried: restarting services, reboot, Cowork Readiness Check (passes)
Cowork tab still not showing in Claude Desktop