How to Fix Claude Workspace VM Service Not Running

When you open Cowork in Claude Desktop, you may see: “Failed to start Claude’s workspace. VM service not running. The service failed to start.” Regular Claude chat still works, but every Cowork task fails before it begins.

Cowork runs inside a small Linux virtual machine. A background service has to boot that VM before Cowork can do anything. When that service fails or its dependencies are missing, you get this error.

This guide walks through the exact fixes that clear the “failed to start claude workspace vm” error, starting with the fastest ones. Work through them in order and stop once Cowork loads.

Why the Claude Workspace VM Fails to Start

On Windows, Cowork runs inside a VM managed by a service called CoworkVMService. That service depends on Hyper-V, Virtual Machine Platform, and the WSL2 kernel. When any part of that chain is missing or stopped, the VM cannot boot.

The most common trigger is CoworkVMService itself. It installs with startup type set to Manual, so it relies on Claude Desktop to start it. A Windows update, a crash, or a wake from sleep can break that handoff and leave the service stopped.

Other causes include disabled virtualization features, a stale VM cache after a Claude Desktop update, missing VM disk files, and network subnet conflicts.

Check the Diagnostic Log First (Windows)

Before trying any fix, check the log to find the actual failure reason. Open PowerShell as administrator and run:

Get-Content "$env:APPDATA\Claude\logs\cowork_vm_node.log" -Tail 30

Then check both services:

Get-Service CoworkVMService | Format-List Name, Status, StartType
Get-Service vmms | Format-List Name, Status, StartType

vmms is the Hyper-V Virtual Machine Management service. If vmms is stopped, go straight to Fix 3. If vmms is running but CoworkVMService is stopped, start with Fix 1 and Fix 2.

Log message guide:

rootfs.vhdx missing or no bundle directory, go to Fix 5
sessiondata.img preserved after reinstall, go to Fix 5 (full manual delete, not the menu option)
Request timed out: stopVM, go to the race condition fix in Fix 2
EBADF: bad file descriptor, go to Fix 5 then Fix 6

Fix 1: Fully Quit and Relaunch Claude Desktop

Closing the window is not the same as quitting. Claude keeps running in the system tray.

Right-click the Claude icon in the system tray (bottom right, near the clock).
Click Quit.
Wait ten seconds.
Open Claude Desktop and click the Cowork tab.
Give the VM 30 to 60 seconds to boot.

If Cowork still fails after relaunch, move to Fix 2.

Fix 2: Start the CoworkVMService Manually (Windows)

Press Windows key, type PowerShell, right-click it, and choose Run as administrator.
Run:

Start-Service CoworkVMService

Relaunch Claude Desktop and open the Cowork tab.

If the command returns an error saying the service does not exist, move to Fix 3.

Do not force-kill Claude via Task Manager: Killing Claude processes leaves Hyper-V resources in a dirty state. CoworkVMService crashes immediately on the next launch because those resources were never released. Always quit using File > Exit and wait at least 60 seconds before reopening. The cowork-svc.exe process will still appear in Task Manager after you exit. That is normal.

Race condition fix: If the log shows Request timed out: stopVM, Claude Desktop tried to start CoworkVMService before the VM bundle finished downloading. Delete vm_bundles (Fix 5), let Claude redownload, watch the log for All files ready, then manually run Start-Service CoworkVMService.

If the race condition keeps recurring, create a scheduled task to delay the service start by 30 seconds:

Set-Content "$env:USERPROFILE\start-cowork.ps1" 'Start-Sleep 30; Start-Service CoworkVMService'

Register-ScheduledTask -TaskName "StartCoworkVM" `
  -Action (New-ScheduledTaskAction -Execute "powershell.exe" `
    -Argument "-WindowStyle Hidden -File $env:USERPROFILE\start-cowork.ps1") `
  -Trigger (New-ScheduledTaskTrigger -AtLogOn -User $env:USERNAME) `
  -Settings (New-ScheduledTaskSettingsSet -AllowStartIfOnBatteries) `
  -RunLevel Highest `
  -Description "Delayed CoworkVMService start after Claude Desktop"

If the service starts but Cowork still fails, move to Fix 4.

Fix 3: Enable Hyper-V and Virtual Machine Platform (Windows)

The Cowork installer does not always enable the Windows features it needs.

Through Windows Features:

Press Windows key, type Turn Windows features on or off, and open it.
Tick Hyper-V, Virtual Machine Platform, and Windows Subsystem for Linux.
Click OK and restart when prompted.

Through PowerShell (faster):

Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All -All
Enable-WindowsOptionalFeature -Online -FeatureName VirtualMachinePlatform -All

Reboot after the commands finish, then open Cowork.

Note: Hyper-V is not available on Windows 11 Home. If you are on Home edition, enable Virtual Machine Platform and WSL2, then test Cowork.

Fix 4: Clear the Cache and Restart From the Menu

In Claude Desktop, open the Help menu.
Go to Troubleshooting.
Click Clear cache and restart.

If the error returns after the restart, the VM disk files themselves are likely corrupted; move to Fix 5.

Fix 5: Delete the VM Bundle to Force a Clean Rebuild

The built-in “Reinstall workspace” menu option preserves sessiondata.img and rootfs.img.zst, which are the files most likely to be corrupted. You need to delete the entire bundle folder manually.

Quit Claude Desktop from the system tray. Then open PowerShell as administrator and run:

Get-Process -Name "*claude*" -ErrorAction SilentlyContinue | Stop-Process -Force
Get-Process -Name "*cowork*" -ErrorAction SilentlyContinue | Stop-Process -Force

Press Windows key + R, type the path below, and press Enter:

%APPDATA%\Claude\vm_bundles

Delete the entire vm_bundles folder.
Relaunch Claude Desktop and open Cowork. Monitor the log:

Get-Content "$env:APPDATA\Claude\logs\cowork_vm_node.log" -Tail 15

Once you see All files ready, start the service:

Start-Service CoworkVMService

If that folder is empty, the VM may be under the packaged app path:

C:\Users\<your-username>\AppData\Local\Packages\Claude_<id>\LocalCache\Roaming\Claude\vm_bundles

If the error appeared right after a Claude Desktop update, also run Fix 6. Otherwise, skip to Fix 8.

Fix 6: Clear the Stale SDK Cache After an Update

After a Claude Desktop update, the VM can keep using an old cached runtime that no longer matches the app.

Quit Claude Desktop from the system tray.
Press Windows key + R, type the path below, and press Enter:

%APPDATA%\Claude\claude-code-vm

Delete the claude-code-vm folder.
Relaunch Claude Desktop.

Use this fix when the error first appears right after a Claude Desktop update.

Fix 7: Fix “Failed to Start Workspace” on macOS

Quit Claude Desktop. If it will not close, open Terminal and run:

pkill -9 "Claude"

Clear the Cowork cache and session data:

rm -rf ~/.cowork/cache
rm -rf ~/.cowork/tmp
rm -rf ~/Library/Application\ Support/com.anthropic.claude/cowork

Reopen Claude from your Applications folder.
Open Cowork and re-add your workspace folder with Add Folder if prompted.

Fix 8: Free Up Disk Space

The VM needs free space to write temporary files. When the disk runs low, the VM fails to start or crashes mid-task with an ENOSPC: no space left on device error.

Clear at least a few gigabytes, empty the Recycle Bin, and restart Claude Desktop.

Fix 9: Reinstall Claude Desktop

Uninstall Claude Desktop through Windows Settings or drag it to Trash on Mac.
Delete the leftover Claude folder in %APPDATA% (Windows) or ~/Library/Application Support/com.anthropic.claude (Mac).
Download the latest version from the official Claude site and install it.
Sign in and open Cowork.

For most users, Fix 1 through Fix 3 clear the error. A full quit and relaunch handles session-related crashes, a manual service start covers cases where Windows failed to boot it automatically, and enabling Hyper-V resolves missing virtualization features. Fix 5 handles the stubborn cases where the VM disk itself is corrupted. Fix 6 targets post-update breakage specifically.

If none of the fixes stick, check for a new Claude Desktop release. Anthropic patches VM startup bugs regularly, and the fix may already be in the latest build.