[BUG] cowork-virtualization-bug-report

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?

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet (closest matches: #27316, #27420 — both closed, but the error persists on current build/hardware below)
• [x] This is a single bug report
• [x] I am using the latest version of Claude Desktop

What's Wrong?

Cowork fails to start with:

Claude's workspace failed to start with HRESULT 0x80370102 (hypervisor not running).
Hardware virtualization (Intel VT-x or AMD-V) is disabled in this device's firmware. Enable it in BIOS/UEFI settings and restart. On devices with a firmware password or vendor management (Dell Command, HP BCU, Lenovo, vPro), this may need to be changed via that tool.

This message is incorrect — hardware virtualization is confirmed enabled at every level (see diagnostics below). This appears to be the same underlying issue reported in #27316 and #27420 (both closed), but it is still occurring on current hardware/build.

Diagnostics Performed (all passed / ruled out)

1. Task Manager → Performance → CPU: Virtualization = Enabled
2. Get-WindowsOptionalFeature -Online -FeatureName VirtualMachinePlatform: State = Enabled
3. Get-Service vmcompute, hns: Both Running
4. Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-Hypervisor: Enabled
5. msinfo32 System Summary:

• Hyper-V - VM Monitor Mode Extensions: Yes
• Hyper-V - Second Level Address Translation: Yes
• Hyper-V - Virtualization Enabled in Firmware: Yes
• Hyper-V - Data Execution Prevention: Yes
• Virtualization-based security: Not enabled (expected/not a conflict)

1. bcdedit: hypervisorlaunchtype = Auto
2. VirtualBox conflict ruled out — VirtualBox was previously installed; confirmed no leftover driver services:

• sc query vboxdrv → service does not exist

1. Full restarts performed (not sleep/fast startup) after each change — error persists unchanged
2. %APPDATA%\Claude\logs does not exist at all — suggests the Cowork VM process never attempts to initialize, so no logs are ever written

System Details

• Device: Lenovo laptop
• OS: Windows (please fill in exact build via winver)
• Claude Desktop version: (please fill in — Help → About)
• CPU: (please fill in — confirmed VT-x supported and enabled)

Additional Information

This closely mirrors #27420 ("Cowork shows 'Virtualization is not enabled' on Windows 10 despite Hyper-V fully enabled (Lenovo ideapad)"), which was closed as a duplicate of #27316. #27316 is also closed but the symptom is still reproducing on current builds/hardware, with a more complete diagnostic trail than either prior report (including ruling out VirtualBox driver conflicts and confirming the Hyper-V-Hypervisor feature specifically, not just Virtual Machine Platform). Reopening or linking this as a regression against those threads may help.

What Should Happen?

Cowork should detect that virtualization is fully enabled at the firmware, Windows feature, and service level, and start the VM successfully.

Error Messages/Logs

Claude's workspace failed to start with HRESULT 0x80370102 (hypervisor not running).

Hardware virtualization (Intel VT-x or AMD-V) is disabled in this device's firmware. Enable it in BIOS/UEFI settings and restart. On devices with a firmware password or vendor management (Dell Command, HP BCU, Lenovo, vPro), this may need to be changed via that tool.

Steps to Reproduce

1. Install/update to latest Claude Desktop on Windows
2. Confirm all virtualization prerequisites above (firmware, Windows features, services)
3. Open Claude Desktop → Cowork tab
4. Observe HRESULT 0x80370102 error despite all checks passing
5. Confirm %APPDATA%\Claude\logs folder does not exist

Claude Model

_No response_

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude 1.26832.0 (056ee2) 2026-08-06T05:43:05.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_