[BUG] Cowork shows 'Virtualization is not available' despite all services running and Hyper-V fully configured

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?

Potentially related issues: #29887, #27316, #27330, #27384, #27420, #32004

Environment

• OS: Windows 11 Pro, Version 25H2, Build 26200
• Claude Desktop: v1.1.7464.0
• Subscription: Pro
• Install method: ClaudeSetup.exe from claude.ai/download (installs as MSIX/AppX)

Verified Prerequisites ✅

| Check | Result |
|---|---|
| Windows Edition | Professional (upgraded from Home during troubleshooting) |
| Virtual Machine Platform | Enabled |
| Windows Hypervisor Platform | Enabled |
| Hyper-V | Enabled |
| hypervisorlaunchtype (bcdedit) | Auto |
| CoworkVMService | Running (Automatic) |
| vmcompute | Running (Manual) |
| Get-VMHost | Returns valid Hyper-V path (C:\ProgramData\Microsoft\Windows\Hyper-V) |

What's Wrong

Cowork permanently shows "Virtualization is not available — Claude's workspace requires Virtual Machine Platform, but the virtualization service isn't responding." despite all virtualization prerequisites being fully satisfied.

The %APPDATA%\Claude\logs\cowork_vm_node.log file is never created, indicating the VM never attempts to initialise. The app appears unable to communicate with CoworkVMService even though the service is confirmed running.

What Should Happen?

Expected Behaviour

Cowork should detect that all virtualization prerequisites are met and successfully initialise the VM workspace.

Error Messages/Logs

### Installation Issues Encountered

The ClaudeSetup.exe installer repeatedly failed with `HRESULT 0x80073CF6` (AddPackage conflict) when CoworkVMService was already present from a previous install, with the log showing:


WARNING: CoworkVMService already exists (potential conflict)
WARNING: failed to remove conflicting service: could not open CoworkVMService: Access is denied.
MSIX installation failed: AddPackage failed with HRESULT 0x80073CF6


This required multiple full uninstall/reinstall cycles including manually removing AppX packages and leftover service registrations before a clean install succeeded.

Steps to Reproduce

Steps to Reproduce

1. Install Claude Desktop on Windows 11 Pro with all Hyper-V features enabled
2. Ensure CoworkVMService and vmcompute are both running
3. Open Claude Desktop → navigate to Cowork tab
4. Observe: "Virtualization is not available" error — VM never initialises

Actual Behaviour

Cowork shows the virtualization error indefinitely. The VM never attempts to start. No cowork_vm_node.log is ever created.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Desktop: v1.1.7464.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Additional Notes

• Machine was originally Windows 11 Home — upgraded to Pro during troubleshooting
• First install attempt (on Home) showed Windows edition: Core in installer log
• Subsequent installs correctly show Windows edition: Professional
• Chat functionality works normally; only Cowork is affected
• ClaudeSetup.log available on request

Done extensive troubleshooting with Claude before it recommended filing bug report (and assisted with info)