Fix 0XC0000707 ALPC Port Request Not Allowed

The 30-Second Fix

Restart your machine. Not shutdown and boot — I mean a full restart. I've seen this error pop up when a service crashes mid-handshake and leaves the ALPC port in a half-open state. A reboot clears that. Had a client last week whose accounting software threw this constantly after an update. Reboot killed it for good.

If you can't restart right now, try restarting just the service that's failing. Open Task Manager, find the process tied to the app giving you the error, right-click and hit End Task. Then relaunch the app. It works maybe 40% of the time if the error is transient.

The 5-Minute Fix

Still broken? Check if a background service is blocking your ALPC port. Run services.msc and look for anything related to RPC (Remote Procedure Call) or your app's own service. Make sure they're running, not stuck on Starting or Stopped. I've seen the RPC Endpoint Mapper service hang after a Windows update.

Next, open an admin command prompt and run netstat -ano | findstr :0. Look for any process using ALPC ports (they show as ALPC in the protocol column). If you see a PID that matches your problem app, note it. Then run taskkill /PID [PID] /F to kill it hard. Wait 10 seconds, then restart the app.

If it's a driver-related ALPC error (common with antivirus or VPN software), disable that software temporarily. For example, if you use Cisco AnyConnect or similar VPN clients, disconnect and close the client completely. Restart the app that errored out. If it works, you've found the conflict — update or reinstall the VPN driver.

The 15+ Minute Fix

This error can also stem from a corrupted ALPC port stack. You'll know because the error persists across reboots and you see it in Event Viewer under System log with source ALPC. Here's the ugly fix:

1. Boot into Safe Mode with Networking. This loads only essential drivers and services. If the error doesn't show in Safe Mode, a third-party driver or service is the culprit.
2. Once in Safe Mode, open an admin command prompt and run sfc /scannow. Let it finish. Then run DISM /Online /Cleanup-Image /RestoreHealth. These fix system file corruption that can corrupt ALPC port allocation.
3. Reboot normally. If the error returns, open Device Manager and look for any device with a yellow exclamation — especially network adapters, storage controllers, or system devices. Right-click and uninstall the driver, then scan for hardware changes to reinstall it fresh. ALPC relies on kernel-mode drivers, so a bad driver there will cause exactly this error.
4. Still here? Check for a pending Windows update. Go to Settings > Windows Update and install any pending updates, especially cumulative updates. Microsoft has patched ALPC-related bugs in several updates since 2020.
5. Worst case: reset the Winsock catalog. Run netsh winsock reset as admin, then netsh int ip reset. Reboot. This tears down and rebuilds the network stack, which includes ALPC infrastructure. I've fixed a stubborn case on a Server 2016 box this way after Citrix broke things.

If nothing above works, you're looking at a corrupted user profile or a very specific app bug. Create a new local admin account and try the app there. If it works, migrate your data and ditch the old profile. Or contact the app vendor — they might have a hotfix for a known ALPC issue in their code.

One more thing: never ignore this error if it shows up repeatedly. ALPC is how Windows apps talk to each other quickly. Letting it slide means apps silently fail or crash later. Fix it now, save the headache.