[BUG] [BUG] Cowork VM fails to start on Windows ARM64 (Samsung Galaxy Book4 Edge, Snapdragon)

[DarrylC73]

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

Environment

• Device: Samsung Galaxy Book4 Edge (NP750XQA-KB2UK)
• Processor: Snapdragon (ARM64)
• OS: Windows 11 Home, Build 10.0.26200
• Claude Desktop: v1.1.9310.0 (MSIX, ARM64)
• Architecture confirmed: Arm64 via Get-AppxPackage

Problem

Cowork workspace fails to start. Three different errors appear depending on the sequence of troubleshooting steps:

1. EBUSY: resource busy or locked, open 'C:\Users\darry\AppData\Roaming\Claude\vm_bundles\claudevm.bundle\smol-bin.vhdx'
2. VM service not running. The service failed to start.
3. VM connection timeout after 60 seconds

The VM bundle downloads successfully (progress bar completes to 100%), but the VM itself never boots.

Services status

CoworkVMService and vmcompute both exist and can be manually started:

What Should Happen?

Running CoworkVMService Claude
Running vmcompute Hyper-V Host Compute Service

and then Claude Cowork Workspace should run with Virtual Machine

Error Messages/Logs

However, even with both running, Cowork times out after 60 seconds.

## What I've tried
- Enabled VirtualMachinePlatform via Admin PowerShell (succeeded, RestartNeeded: False)
- `Microsoft-Hyper-V-All` returns "Feature name is unknown" on ARM64
- Manually started vmcompute and CoworkVMService — both start, but VM still times out
- Deleted vm_bundles folder and let Claude re-download fresh — same result
- Full uninstall and reinstall of Claude Desktop
- Multiple reboots
- Stopped all services and processes before relaunching
- BIOS (Samsung Aptio Setup Utility) has no virtualization toggle — Snapdragon has no VT-x/AMD-V equivalent
- `VirtualizationFirmwareEnabled` reports False on ARM64 (expected — not applicable to Snapdragon)

## Log file locations
Logs are at: `C:\Users\darry\AppData\Roaming\Claude\logs\`
- cowork-service.log (736 KB)
- cowork_vm_node.log (275 KB)
- coworkd-user-S-1-5-21-*.log (495 KB)
- main.log (9.8 MB)

## Related issues
- #29428 (VM service not running — Windows 11 Home)
- #30566 (VM not running on Snapdragon X Elite)
- #28779 (ARM64 installer issues on Snapdragon X)
- #32004 (Virtual Machine Platform not available despite features enabled)

Steps to Reproduce

AS above

claude-debug-logs.zip

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

Claude Desktop:** v1.1.9310.0 (MSIX, ARM64)

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

cowork-service.log
coworkd-user-S-1-5-21-3309502803-3079381605-1452027300-1001.log
coworkd.log
main1.log
claude_vm_node.log
main.log
cowork_vm_node.log
claude.ai-web.log
unknown-window.log
gpu-info.json
mcp-info.json
supported-features-info.json
system-info.txt

claude-debug-logs.zip

[erigney-wq]

Can reproduce on a different Snapdragon device.

Environment

• OS: Windows 11 Pro (ARM64)
• CPU: Snapdragon (different device from OP)
• Claude Desktop: v1.1.9310.0 (arm64)
• Package: Claude_1.1.9310.0_arm64__pzs8sxrjxfjjc

Symptoms
Same as OP — Cowork spins indefinitely on first setup, VM never boots.

Hyper-V event log shows:

Create compute system, result 0xC0370103
Start compute system, result 0xC0370103

0xC0370103 = HCS_E_HYPERV_NOT_INSTALLED — "The virtual machine could not be started because a required feature is not installed."

Additional finding: smol-bin.arm64.vhdx is present in the package resources but is NOT automatically copied to %APPDATA%\Claude\vm_bundles\claudevm.bundle on first launch. Manual copy did not resolve the issue.

All Hyper-V features are enabled:

• VirtualMachinePlatform: Enabled
• HypervisorPlatform: Enabled
• Microsoft-Hyper-V-All: Enabled
• Microsoft-Hyper-V-Hypervisor: Enabled
• hypervisorlaunchtype: Auto

cowork_vm_node.log is never created — failure occurs before logging initializes.

This appears to be a Snapdragon ARM64 platform compatibility issue rather than a configuration problem. Happy to provide additional diagnostics if helpful.

[erigney-wq]

#30566 was a similar issue and incorrectly closed as a duplicate. It is not a duplicate of #29428 or #29941. Those issues are about signature verification failures and general service startup errors on x64 hardware. This issue is specifically about Snapdragon ARM64 platform compatibility — the VM fails with 0xC0370103 (HCS_E_HYPERV_NOT_INSTALLED) even with all available Hyper-V features enabled.

I can reproduce #30566 on a separate Snapdragon ARM64 device (Windows 11 Pro, Claude Desktop v1.1.9310.0 ARM64). The root cause appears to be that Cowork's VM configuration requires a Hyper-V capability that Qualcomm's hypervisor implementation does not expose — this is fundamentally different from the errors in the linked issues.

Please keep both issues open as a distinct ARM64/Snapdragon tracking issue.

[sea-andy]

Can reproduce on a newer Claude Desktop build.

Environment

• Device: Snapdragon X laptop
• OS: Windows 11 Home 24H2 (Build 26200)
• Claude Desktop: v1.1.9493.0 (ARM64 MSIX from claude.ai/api/desktop/win32/arm64/msix/latest/redirect)
• Virtualization features: HypervisorPlatform Enabled, VirtualMachinePlatform Enabled
• Full Hyper-V: Not available (Windows 11 Home — no vmms service, Get-VMSwitch not recognized)

Symptoms

Same as OP — cycles through all three errors depending on state:

1. EBUSY: resource busy or locked on smol-bin.vhdx
2. VM service not running. The service failed to start.
3. VM connection timeout after 60 seconds

New finding: invalid JSON in Hyper-V Compute logs

The Hyper-V Compute Admin event log shows this error on every Cowork attempt:

The specified property query is invalid: The virtual machine or container JSON document is invalid.
(0xC037010D, 'Invalid JSON document '$'').

This suggests the VM config JSON being passed to the Host Compute Service is empty or malformed. This error appears in Get-WinEvent -LogName "Microsoft-Windows-Hyper-V-Compute-Admin" and occurs consistently on every startup attempt.

What I confirmed

• smol-bin.arm64.vhdx IS copied to the bundle directory on this version (v1.1.9493.0) — the log shows it explicitly
• The VM boot step and add_plan9_shares both complete successfully
• The failure is at guest connection — the host polls for 60 seconds and never gets a response
• vmcompute service starts successfully but logs the invalid JSON error above
• Deleting vm_bundles and letting it re-download (~11 GB) does not help
• Reinstalling the workspace does not help

Relevant log snippet (cowork_vm_node.log)

[VM:start] Copying smol-bin.arm64.vhdx to bundle: ...smol-bin.arm64.vhdx -> ...smol-bin.vhdx
[VM:start] smol-bin.arm64.vhdx copied successfully
[VM:start] Configuring Windows VM service...
[VM:start] Windows VM service configured
[VM:steps] create_network completed (0ms)
[VM:steps] create_vm_config completed (60ms)
[VM:steps] vm_boot completed (115ms)
[VM:steps] add_plan9_shares completed (3ms)
[VM:start] Still waiting for guest connection... 10206ms elapsed, 21 polls
...
[VM:start] Connection timeout, last completed step: add_plan9_shares

Notes

This confirms the issue persists in v1.1.9493.0 (newer than OP's v1.1.9310.0). Combined with the Pro user above also failing, this is clearly a Snapdragon ARM64 platform issue regardless of Windows edition. The 0xC037010D invalid JSON error may be a useful lead for the team.

[DarrylC73]

please keep open. Thanks

[melissa794]

Also affected by this issue.
Device info:

Surface Pro
OS: Windows 11 Home 25H2
Architecture: ARM64
Claude Desktop version: v1.1.9493.0 (ARM64, non-Store install)

Symptoms:
The Cowork workspace fails to start with "VM connection timeout after 60 seconds." On subsequent attempts, it fails with "VM service not running. The service failed to start."
What I've tried (all failed):

Confirmed virtualization is enabled in Task Manager
Enabled VirtualMachinePlatform, HypervisorPlatform, and WSL features
Confirmed CoworkVMService is running and set to Automatic
Deleted vm_bundles folder and let Claude re-download
Full uninstall and reinstall of Claude Desktop
Multiple reboots

From cowork_vm_node.log:
The VM boots, copies smol-bin.arm64.vhdx, creates the network, and starts the VM, but gets stuck at "Still waiting for guest connection..." and times out after 60 seconds. On the next attempt, the service itself fails to start at the "Configuring Windows VM service" step.
This appears to be the same ARM64-specific issue. Regular Claude chat works fine — only Cowork is affected.

[parm485-create]

Facing same issue #39161

[gabtomassini]

facing same issue on: Asus A14, Snapdragon X Elite, ARM64
OS: Windows 11 Pro (upgraded from Home), Hyper-V enabled, vmms running
Claude: v1.1.9669.0 ARM64

[jpolousaes]

Facing same issue on Thinkpad Thinkbook G7 Snapdragon X Plus, Arm 64
Windows 11 Pro, Hyper-V enabled
Version 1.1.9669 (aea25d)

[marlvinvu]

My Claude says your issue is of the same type as #40147 , #40196, #39527. Let Anthropic pay attention to your issues.