[BUG] Cowork shows "yukonSilver not supported" on Windows 10 Pro 22H2 — VM not supported (win32/x64) 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?

Environment

Claude Desktop Version: Latest (downloaded February 2026)
Platform: Windows 10 Pro
Windows Version: 22H2
OS Build: 19045.6937
Hardware: Lenovo ThinkPad X1
Processor: Intel x64

Virtualization Status (all confirmed enabled):

Intel VT-x (Virtualization Technology): ✅ Enabled in BIOS (greyed out / locked on, confirmed enabled)
Hyper-V: ✅ Enabled via Windows Features
Virtual Machine Platform: ✅ Enabled via Windows Features
Windows Hypervisor Platform: ✅ Enabled via Windows Features
Task Manager → CPU → Virtualization: ✅ Enabled
Hyper-V Virtual Machine Management service: ✅ Running in services.msc

What's Wrong?
Cowork fails to start with a "hardware virtualization required" error. All virtualization features are fully enabled at both the BIOS and Windows level, but the app is incorrectly detecting the platform as unsupported.

Related Issues
This appears related to #25136 (yukonSilver not supported on Windows 11 Pro x64) and #27316 (Cowork shows virtualization error despite Hyper-V enabled on Windows 10 Pro).

What Should Happen?

Expected Behavior
Cowork should detect that hardware virtualization is fully enabled and successfully start the yukonSilver VM on Windows 10 Pro x64.

Actual Behavior
The app's platform detection classifies the system as unsupported and skips VM startup entirely, showing the "hardware virtualization required" error in the UI.

Error Messages/Logs

From %LOCALAPPDATA%\Packages\Claude_pzs8sxjxfjjc\LocalCache\Roaming\Claude\logs\cowork_vm_node.log:
[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
[startVM] VM not supported (win32/x64), skipping
This error repeats on every launch attempt. The VM never starts.

Steps to Reproduce

Steps to Reproduce

Purchase a Claude Pro/Max subscription
Download and install the latest Claude Desktop for Windows from claude.ai/download
Launch Claude Desktop and log in
Navigate to the Cowork tab
Observe "hardware virtualization required" error

Pre-requisite steps taken prior to reproducing (all completed, error persists after each):

Entered BIOS (F1 on ThinkPad) → confirmed Intel Virtualization Technology already enabled
Opened optionalfeatures → enabled Hyper-V → restarted
Opened optionalfeatures → enabled Virtual Machine Platform → restarted
Opened optionalfeatures → enabled Windows Hypervisor Platform → restarted
Confirmed in Task Manager → Performance → CPU → Virtualization: Enabled
Confirmed Hyper-V Virtual Machine Management service running in services.msc
Fully quit and relaunched Claude Desktop after each step above
Error persists at every attempt — log consistently shows yukonSilver not supported (status=unsupported) and VM not supported (win32/x64), skipping

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

calude-sonnet-4-6

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

This might go somewhere else since it is about co-work but claude told me to file it here.