[BUG] Code tab crashes on Windows 11 Home 25H2 after auto-update — VM service not running (regression from working state)

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?

Code tab in Claude Desktop crashes reliably on Windows 11 Home 25H2 (Build 26200).
The VM starts successfully (confirmed via Hyper-V event logs) but the guest OS shuts
itself down within ~2-3 minutes. App UI goes blank and requires end-task to recover.

This is a REGRESSION — the Code tab worked for over a month before breaking around
Feb 16, 2026, coinciding with an auto-update. Reinstalling picked up v1.1.5368 which
remains broken.

CoworkVMService stays Running throughout. Not a resource issue (34GB RAM, Intel Ultra 9).
Not NTFS compression. Clean vm_bundles re-download does not fix it.

Key log evidence:

• cowork_vm_node.log shows: VM starts, network CONNECTED, API REACHABLE, then keepalive

pings time out

• Hyper-V Admin log shows: "guest operating system powered off" — guest halts itself
• main.log shows repeated: "VM service not running. The service failed to start."

What Should Happen?

The Code tab should start and maintain a stable VM session, as it did
successfully for over a month prior to an auto-update around Feb 16, 2026.

Error Messages/Logs

cowork_vm_node.log:
2026-03-06 06:43:38 [info] [VM:start] Startup complete, total time: 17786ms
2026-03-06 06:43:38 [info] [Keepalive] Starting (interval=2000ms)
2026-03-06 06:46:34 [warn] [Keepalive] Ping failed: Keep-alive ping timed out
(repeated timeouts follow)

Hyper-V Admin Event Log:
"cowork-vm started successfully" at 6:44:01
"The guest operating system powered off" at 6:47:08

main.log:
Repeated: "VM service not running. The service failed to start."

Steps to Reproduce

1. Run Claude Desktop v1.1.5368 on Windows 11 Home 25H2 (Build 26200.7840)
2. Click the Code tab
3. VM downloads, starts, and reports network CONNECTED and API REACHABLE
4. Within 2-3 minutes, guest OS shuts itself down cleanly
5. UI goes blank, requires end-task to recover
6. CoworkVMService remains Running throughout

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Unknown — worked for ~1 month before auto-update broke it around Feb 16, 2026

Claude Code Version

1.1.5368

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

• Windows Home edition: Hyper-V unavailable, VMP and HypervisorPlatform enabled
• Intel Core Ultra 9 185H, 34GB RAM — not a resource issue
• Not NTFS compression (verified)
• Deleted vm_bundles and local-agent-mode-sessions, fresh re-download, same result
• Related issues: #24918, #25206, #27801, #27492

While having this issue, Claude Code in VSCode still works.