[BUG] [BUG] Cowork stuck in download loop on Windows 10 Pro — "yukonSilver not supported (status=unsupported)" despite Hyper-V fully 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?

What's Wrong?

Cowork never loads on Windows 10 Pro. The app repeatedly tries to download the VM bundle, fails silently, and retries indefinitely with no error shown in the UI.

The cowork_vm_node.log shows the app's own platform-detection marking the machine as unsupported and deleting the VM bundle in a loop:

[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...

This line repeats on every launch, causing the endless re-download behavior.

Likely root cause:
(Get-ComputerInfo).WindowsProductName reports "Windows 10 Pro", but the DISM Image Version is 10.0.26200, which is a Windows 11 build number. The "yukonSilver not supported" classification persists even after fully enabling virtualization. This strongly suggests the platform-detection logic is misclassifying the OS due to this version mismatch.

Environment:

• OS: Windows 10 Pro (DISM Image Version 10.0.26200)
• Hyper-V: Microsoft-Hyper-V = Enabled, VirtualMachinePlatform = Enabled
• Services: vmms = Running, vmcompute = Running
• Claude Desktop version: [1.12603.1.0]

Steps to Reproduce:

1. Install Claude Desktop on Windows 10 Pro with Hyper-V fully enabled
2. Open the Cowork tab
3. App downloads the VM, never finishes, asks to download again — infinite loop

Expected Behavior:
Cowork detects virtualization is enabled, recognizes the platform as supported, completes the VM download once, and loads the workspace.

Actual Behavior:
Platform is incorrectly classified as unsupported (yukonSilver not supported), the VM bundle is deleted, and the download restarts endlessly — despite the host meeting all stated requirements.

What Should Happen?

Cowork should detect that hardware virtualization is fully enabled (Hyper-V, VirtualMachinePlatform, vmms and vmcompute all active), recognize the Windows platform as supported, complete the VM bundle download once, and load the Cowork workspace successfully — instead of classifying the machine as "unsupported" and restarting the download in an endless loop.

Error Messages/Logs

Steps to Reproduce

1. Install Claude Desktop on Windows 10 Pro with Hyper-V fully enabled (VirtualMachinePlatform enabled, vmms and vmcompute services running)
2. Open the Cowork tab
3. The app begins downloading the VM bundle, never finishes, and asks to download again — repeating in an infinite loop with no error shown in the UI
4. Checking cowork_vm_node.log shows the line "[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported)" repeating on every launch

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.12603.1.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_