[BUG] Cowork "Virtualization is not available" — yukonSilver classified as unsupported on Windows 10 Pro with 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?

Cowork displays "Virtualization is not available — Claude's workspace requires Hyper-V, but the virtualization service isn't responding" on Windows 10 Pro despite all virtualization prerequisites being fully enabled and verified.
The log reveals the actual root cause: Claude Desktop classifies this system's hardware profile (yukonSilver) as unsupported before attempting to boot the VM. Every subsequent VM boot attempt then fails with HRESULT 0x80370102 ("Hyper-V is not installed on the host"), which is contradicted by all system-level checks.
OS | Windows 10 Pro x64
Claude Desktop version | 1.1.4498.0
Install type | Microsoft Store (MSIX)

CoworkVMService | ✅ Running
vmcompute service | ✅ Running
Microsoft-Hyper-V feature | ✅ Enabled
HypervisorPlatform | ✅ Enabled
VirtualMachinePlatform | ✅ Enabled
bcdedit hypervisorlaunchtype | ✅ Set to Auto
Restarted computer multiple times | ✅ Done
Reinstalled Claude Desktop | ✅ Done

What Should Happen?

Cowork should detect that Hyper-V is enabled and operational on this Windows 10 Pro system and successfully launch the workspace VM.
Actual Behaviour
Claude Desktop's internal platform classifier marks this hardware profile (yukonSilver) as unsupported, which prevents VM boot entirely. The HCS error is a downstream consequence of that classification, not an independent system misconfiguration.
Note: Restarting the computer does not resolve this. All standard troubleshooting steps have been exhausted. This appears to be the same yukonSilver classification issue reported in #25136 and related issues.

Error Messages/Logs

2026-03-05 18:17:28 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-03-05 18:19:56 [warn] [startVM] VM not supported (win32/x64), skipping

2026-03-05 18:27:47 [error] [VM:start] VM boot failed: HCS operation failed: failed to create compute system: HcsWaitForOperationResult failed with HRESULT 0x80370102: {"ErrorMessage":"The virtual machine could not be started because a required feature is not installed.","ErrorEvents":[{"Message":"Cannot create system 'cowork-vm' since Hyper-V is not installed on the host."}]}

2026-03-05 18:27:47 [error] [VM:start] HCS error detected, available=true, missing=[], sentinel=HYPERVISOR_SERVICE_ERROR

Steps to Reproduce

1. Open Claude Desktop App
2. Select Cowork Tab
3. Wait 10 seconds for this to appear:

Virtualization is not available
Claude's workspace requires Hyper-V, but the virtualization service isn't responding. Restart your computer to resolve this.

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Desktop version | 1.1.4498.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

I debugged this with Claude to sign at 4.6. So everything I've written into this, except for this bit, came directly from Claude. Including the instructions on how to log this bug