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⚡ Quick Cowork Fixes

Before trying advanced troubleshooting steps, start with these simple fixes. They resolve many Cowork startup issues without touching BIOS, PowerShell, or system settings.

1. Quit Cowork Completely

Closing the window does not fully stop Cowork — the VM may still be running in the background.

Fix:
Right‑click the Cowork tray icon → Quit Cowork, wait 5 seconds, then relaunch.

Why it helps:
Clears stuck VM sessions, stale mounts, and hung processes.

2. Restart CoworkVMService (GUI Only)

You can restart the service without using PowerShell.

Fix:
1. Press Ctrl + Shift + Esc
2. Go to Services
3. Find CoworkVMService
4. Right‑click → Restart

Why it helps:
Resets the VM, virtiofs, Plan9 mounts, and HCS handles.

3. Close All WSL Terminals

WSL keeps the hypervisor active even when minimized.

Fix:
Close all: - Windows Terminal
- PowerShell
- CMD
- VS Code Remote WSL sessions

Why it helps:
Releases WSL’s VM so Cowork can start its own.

4. Quit VS Code (Especially Remote WSL)

VS Code Remote WSL silently keeps WSL running.

Fix:
Fully quit VS Code before launching Cowork.

Why it helps:
Prevents WSL from reserving Hyper‑V resources.

5. Quit Virtualization Apps

These apps auto‑start and reserve virtualization resources:

  • Docker Desktop
  • VirtualBox
  • VMware Workstation
  • QEMU
  • Android emulators (BlueStacks, LDPlayer, Nox)

Fix:
Quit these apps before launching Cowork.

Why it helps:
Prevents hypervisor conflicts and VM resource contention.

6. Disconnect VPN / Tunneling Apps

VPNs create virtual network adapters that block Hyper‑V networking.

Common offenders: - Tailscale
- ZeroTier
- NordVPN
- ExpressVPN
- Cisco AnyConnect
- GlobalProtect
- Cloudflare WARP

Fix:
Disconnect or quit the VPN app, then relaunch Cowork.

Why it helps:
Allows Cowork’s VM to obtain an IP address and create its NAT network.

7. Reboot After Windows Updates

Windows updates often leave Hyper‑V or HNS in a partially updated state.

Fix:
Restart your PC, then launch Cowork before opening other apps.

Why it helps:
Resets Hyper‑V, HNS, WinNAT, and VM state files.

8. Close Other Running VMs

Hyper‑V allows only one VM to reserve certain resources at a time.

Fix:
Close any running VM from: - Hyper‑V Manager
- VirtualBox
- VMware

Why it helps:
Ensures Cowork’s VM can start cleanly.

9. Log Out and Back In

A fast way to reset user‑session virtualization handles.

Fix:
Sign out → sign back in → launch Cowork.

Why it helps:
Clears stale HCS handles and locked VHDX files.

10. Ensure Only One Cowork Instance Is Running

Launching Cowork twice can cause mount failures.

Fix:
Quit all Cowork windows, then relaunch a single instance.

Why it helps:
Prevents duplicate VM initialization attempts.

Windows Quick Fixes- Claude Cowork Troubleshooting Guide Created by ArchieCur in collaboration with Copilot (Microsoft) version 1.0.0 June 2026