[BUG] Cowork "Virtualization is not available" — all features enabled, VM never initializes

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?

OS: Windows 11 (Build 26200.8457)
Claude Desktop: latest version from claude.ai/download
Subscription: Pro
Verified configuration:

VirtualMachinePlatform: Enabled
Hyper-V (Microsoft-Hyper-V-All): Enabled
CoworkVMService: Running / Automatic
hypervisorlaunchtype: Auto

Problem: Cowork tab permanently shows "Virtualization is not available — Claude's workspace requires Virtual Machine Platform, but the virtualization service isn't responding." Restarting does not resolve it. Chat and Code tabs work normally — only Cowork is affected.
Steps taken: Enabled Hyper-V via PowerShell as administrator, restarted. Issue persists.
This appears to be the same bug reported in #29887, #32004, #45715, #51813.

What Should Happen?

Cowork should detect that all virtualization features are enabled and successfully start the VM workspace.

Error Messages/Logs

Virtualization is not available. Claude's workspace requires Virtual Machine Platform, but the virtualization service isn't responding.

Steps to Reproduce

1. Install Claude Desktop (latest) from claude.ai/download on Windows 11
2. Open Claude Desktop and navigate to the Cowork tab
3. Observe "Virtualization is not available" error immediately
4. Restarting the computer does not resolve the issue

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude Desktop (not Claude Code CLI)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Verified configuration via PowerShell (admin):

• VirtualMachinePlatform: Enabled
• Microsoft-Hyper-V-All: Enabled
• CoworkVMService: Running / Automatic
• hypervisorlaunchtype: Auto

Same issue reported in #29887, #32004, #45715, #51813. Chat and Code tabs work normally — only Cowork is affected.