“Failed to Start Workspace / Can’t Reach Claude API” and “sdk-daemon not connected” on Windows 11?

If you’ve just opened Claude Desktop on Windows 11 and ran into one of these errors in the Cowork tab, you’re not alone — and the fix is simpler than you think.

The Errors

Claude Cowork users on Windows 11 (Home and Pro) frequently encounter two errors that block the workspace from starting:

Error 1:

“Failed to start Claude’s workspace — Can’t reach the Claude API from Claude’s workspace.”

Sometimes preceded by:

“Taking longer than expected to reach the Claude API…”

Error 2:

“sdk-daemon not connected”

Both errors appear even when your internet connection works perfectly and regular Claude Chat mode has no issues. The Cowork tab simply refuses to start.

What’s Actually Happening

Claude Cowork doesn’t run directly on your machine. It runs inside a dedicated Linux virtual machine powered by Hyper-V (or more precisely, Microsoft’s Host Compute Service). This VM is managed by a Windows service called CoworkVMService.

Here’s the catch: that service can stop running on its own — after a reboot, a Windows update, a sleep/wake cycle, or seemingly at random. When CoworkVMService is stopped, the Cowork VM can’t boot, the virtual network adapter never gets created, and Claude Desktop shows you cryptic error messages about the API being unreachable.

The errors are misleading. Your internet is fine. The Claude API is fine. It’s the local VM service that isn’t running.

The Fix (3 Steps)

Step 1: Force Close Claude Desktop

Close Claude Desktop completely. Don’t just click the X — the app often keeps running in the background.

Open Task Manager (Ctrl + Shift + Esc), go to the Processes tab, and end every instance of Claude. Look for entries named “Claude” or “Claude Desktop” and click “End Task” on each one.

Step 2: Restart the CoworkVMService

Open PowerShell as Administrator:

• Right-click the Start menu
• Select Terminal (administrateur) (or “Windows Terminal (Admin)” in English)

Then run:

Start-Service CoworkVMService

NO output means it worked. If you want to verify:

Get-Service CoworkVMService

You should see:

Status   Name               DisplayName

 ------      -----                      -----------

Running  CoworkVMService    Claude

Step 3: Relaunch Claude Desktop

Open Claude Desktop and navigate to the Cowork tab. Give it 30 seconds to a minute — the VM needs time to boot up and establish its network connection.

That’s it. Cowork should now start successfully.

 

Quick Reference: One-Liner Fix for the error “Failed to start Claude’s workspace”

For those who want a copy-paste solution, open PowerShell as Admin and run:

Stop-Process -Name "Claude" -Force -ErrorAction SilentlyContinue; Start-Service CoworkVMService

Then relaunch Claude Desktop.

Why Does This Keep Happening?

The CoworkVMService is installed with its startup type set to Manual, not Automatic. This means the service doesn’t start on boot — it relies on Claude Desktop to trigger it. When something interrupts that handshake (a crash, a Windows update, a wake from sleep), the service stays stopped and Cowork breaks.

Unfortunately, changing the startup type to Automatic via PowerShell is blocked by access restrictions on the service. This is a known issue reported on Anthropic’s GitHub (issues #24918, #25241, #27010). Anthropic will likely ship a proper fix in a future update.

Until then, restarting CoworkVMService manually is the reliable workaround.

Frequently Asked Questions

Do I need Windows 11 Pro for Claude Cowork?

Not necessarily. Cowork can work on Windows 11 Home, though Home editions lack some Hyper-V components (like full WinNAT support) that can cause additional issues. If you encounter “Classe non valide” errors when running Get-NetNat, you may be hitting a Home-edition limitation that requires a different workaround or an upgrade to Pro.

Does NordVPN / other VPNs affect Cowork?

VPN software can interfere with Cowork’s virtual networking, even when disconnected. The VPN TAP adapter can conflict with Cowork’s Hyper-V NAT setup. If you’re experiencing persistent issues, try fully quitting your VPN application (not just disconnecting — close the app entirely).

I see “Virtualization is not enabled” but it is enabled in BIOS

This is a separate issue. Make sure the following Windows features are turned on (Paramètres → Applications → Fonctionnalités facultatives → Plus de fonctionnalités Windows):

• Plateforme de machine virtuelle (Virtual Machine Platform)
• Plateforme d’hyperviseur Windows (Windows Hypervisor Platform)

Restart after enabling them.

The fix works but I have to do it every time I reboot

Yes, this is expected until Anthropic patches the service startup behavior. You can create a shortcut to automate it:

1. Right-click your Desktop → New → Shortcut
2. Paste: powershell the following Command : Start-Service CoworkVMService
3. Name it “Start Cowork Service”
4. Right-click the shortcut → Properties → Advanced → check Run as administrator

Double-click this shortcut after each reboot, then launch Claude.

Where are the Cowork logs?

Depending on your install method:

• Microsoft Store install: %LOCALAPPDATA%\Packages\Claude_*\LocalCache\Roaming\Claude\logs\
• Direct install: %APPDATA%\Claude\logs\

Look for cowork_vm_node.log to see detailed VM startup information.

---

Want to go further with AI process and tools at your company? Contact Z Digital Agency — we help businesses integrate AI tools into their workflows.