[BUG] Cowork tab shows "yukonSilver not supported" on Windows 11 Pro — persists on latest version despite all prerequisites met

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?

What's Wrong?
Cowork fails to initialize on Windows 11 Pro. The cowork_vm_node.log repeatedly shows the platform detection marking the system as unsupported, and the VM never progresses past this check.

Log excerpt (%APPDATA%\Claude\logs\cowork_vm_node.log):

2026-07-21 06:10:48 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...

Steps taken (did not resolve):

Full uninstall via Settings → Apps → Installed apps
Removed %LOCALAPPDATA%\Claude and %LOCALAPPDATA%\claude-updater
Removed stray AppX packages via Get-AppxPackage Claude | Remove-AppxPackage
Fresh install of ClaudeSetup.exe (run as Administrator) from claude.com/download
Confirmed Hyper-V, Virtual Machine Platform, and Windows Hypervisor Platform all enabled in Windows Features
Restarted machine multiple times
Confirmed running the latest Claude Desktop version

Environment:

OS: Windows 11 Pro
Claude Desktop version: [Version 1.22209.3 (babe11)]
Install method: MSIX (fresh install via claude.com/download)

What Should Happen?

Cowork should detect that virtualization prerequisites are met and proceed to download/initialize the VM bundle, rather than marking the platform as unsupported.

Error Messages/Logs

Steps to Reproduce

Steps taken (did not resolve):

Full uninstall via Settings → Apps → Installed apps
Removed %LOCALAPPDATA%\Claude and %LOCALAPPDATA%\claude-updater
Removed stray AppX packages via Get-AppxPackage Claude | Remove-AppxPackage
Fresh install of ClaudeSetup.exe (run as Administrator) from claude.com/download
Confirmed Hyper-V, Virtual Machine Platform, and Windows Hypervisor Platform all enabled in Windows Features
Restarted machine multiple times
Confirmed running the latest Claude Desktop version

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Version 1.22209.3 (babe11)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_