[BUG] Cowork shows "Virtualization is not enabled" on Windows 10 Home despite all virtualization features enabled

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?

The Cowork tab permanently shows "Virtualization is not enabled. Claude's workspace requires hardware virtualization (Hyper-V). Enable virtualization in your computer's BIOS/UEFI settings, then restart." — despite virtualization being active and confirmed at every level.

The %APPDATA%\Claude folder does not exist at all, meaning the Cowork VM never attempts to initialize.

What Should Happen?

Expected Behavior
Cowork should detect that hardware virtualization is active (CoworkVMService running, vmcompute running, VM Monitor Extensions confirmed) and initialize the workspace successfully.

Actual Behavior
Cowork shows the misleading BIOS error and never attempts to start the VM. No logs are generated.

Error Messages/Logs

**Verification Steps Completed**

| Check | Result |
|---|---|
| CoworkVMService | ✅ Running (Automatic) |
| vmcompute service | ✅ Running (Manual) |
| Virtual Machine Platform | ✅ Enabled |
| Windows Hypervisor Platform | ✅ Enabled |
| WSL (Windows Subsystem for Linux) | ✅ Enabled |
| systeminfo Hyper-V | ✅ VM Monitor Mode Extensions: Yes |
| %APPDATA%\Claude folder | ❌ Does not exist — VM never initializes |
| Microsoft-Hyper-V via DISM | ❌ Error 0x800f080c (expected on Windows Home) |

The error log that appears is on Claude Cowork, saying: 
Virtualization not available
Claude's workspace requires Hyper-V, but the virtualization service does not respond. Please restart your computer to solve this (obviously I tried it and it did not work).

Steps to Reproduce

1. Install Claude Desktop (latest) on Windows 10 Home Build 19045 as Administrator
2. Enable Virtual Machine Platform, Windows Hypervisor Platform, and WSL via Windows Features
3. Restart
4. Open Claude Desktop and navigate to the Cowork tab
5. Observe: "Virtualization is not enabled" error — VM never starts, %APPDATA%\Claude folder is never created

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.50

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Environment

• OS: Windows 10 Home
• Version: 2009
• Build: 19045
• Claude Desktop: latest (installed as Administrator)

Additional Notes
The error message directing users to "Enable virtualization in BIOS" is misleading — the issue is a platform detection bug in Claude Desktop, not a system configuration problem. This is reproducible on a clean install. Related to #27316, #27330, #27384, #27420.