[BUG] Cowork tab permanently shows "requires newer installation" banner on Windows 10 — CoworkVMService not registered after clean install

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?

Banner "Cowork requires a newer installation" persists indefinitely.
"Reinstall" button is non-functional (known issue #28998).
CoworkVMService IS running but Claude Desktop ignores it.
Appears to be a platform detection bug misidentifying a valid Windows 10 install.

What Should Happen?

EXPECTED BEHAVIOR

Cowork tab should be accessible. It worked correctly ~2 weeks ago on the same machine.

Error Messages/Logs

Banner "Cowork requires a newer installation" persists indefinitely.
"Reinstall" button is non-functional (known issue #28998).
CoworkVMService IS running but Claude Desktop ignores it.
Appears to be a platform detection bug misidentifying a valid Windows 10 install.

Steps to Reproduce

1. Open Claude Desktop (v1.13576.4) on Windows 10
2. Click the Cowork tab
3. Banner appears: "Cowork requires a newer installation"
4. Click "Reinstall" button → nothing happens
5. Performed full manual uninstall + registry/appdata cleanup
6. Reinstalled from fresh claude.ai/download installer
7. Enabled HypervisorPlatform via PowerShell
8. CoworkVMService confirmed Running
9. Banner still appears, Cowork tab still disabled

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.13576.4

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

ENVIRONMENT

• OS: Windows 10 (as Administrator)
• Claude Desktop version: 1.13576.4 (414f85)
• VirtualMachinePlatform: Enabled
• HypervisorPlatform: Enabled (manually enabled)
• hypervisorlaunchtype: Auto
• CoworkVMService: Running (after manual steps)
• Claude package type: .exe classic installer (not MSIX)
• Cowork previously worked: YES (~2 weeks ago)