Cowork VM connection timeout on Windows 11 Pro ARM64 - guest agent never connects

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 fails to start on Windows 11 Pro ARM64. The VM service starts successfully but times out after 60 seconds waiting for the guest connection. The smol-bin.vhdx file is reported as locked by a running VM in the logs, but no .vhdx file exists anywhere on the filesystem. The last completed step is always load_swift_api.

What Should Happen?

Cowork should start successfully and connect to the workspace.

Error Messages/Logs

2026-06-02 10:50:08 [warn] [VM:start] smol-bin.vhdx locked by running VM (EBUSY), skipping copy
2026-06-02 10:50:08 [info] [VM:start] Configuring Windows VM service...
2026-06-02 10:50:08 [info] [VM:start] Windows VM service configured
2026-06-02 10:50:18 [info] [VM:start] Still waiting for guest connection... 10140ms elapsed, 21 polls
2026-06-02 10:50:28 [info] [VM:start] Still waiting for guest connection... 20343ms elapsed, 41 polls
2026-06-02 10:50:39 [info] [VM:start] Still waiting for guest connection... 30609ms elapsed, 61 polls
2026-06-02 10:50:49 [info] [VM:start] Still waiting for guest connection... 40895ms elapsed, 81 polls
2026-06-02 10:50:57 [info] [startVM] VM startup already in progress, waiting...
2026-06-02 10:50:59 [info] [VM:start] Still waiting for guest connection... 51184ms elapsed, 101 polls
2026-06-02 10:51:08 [error] [VM:start] Connection timeout, last completed step: load_swift_api
2026-06-02 10:51:08 [info] Dispatching startup error: VM connection timeout after 60 seconds
2026-06-02 10:51:08 [error] [VM:start] Startup failed: Error: VM connection timeout after 60 seconds
2026-06-02 10:51:08 [info] [VM:start] Skipping auto-reinstall (already attempted once)

Steps to Reproduce

Install Claude Desktop on Windows 11 Pro ARM64
Attempt to open Cowork
VM service starts but never connects — timeout after 60 seconds every time

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

1.9659.4.0 (arm64)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_