Crucially, the server never even sees the login attempt. The failure happens entirely on the client machine before the request reaches the remote host.
Jump to Solution: Fix RDP Error 0x80080005The Error: 0x80080005
When attempting to connect via the Windows App or standard Remote Desktop Protocol (RDP), the connection fails immediately with:
An authentication error has occurred (Code: 0x80080005)
The Cause
The KB5074109 update breaks the authentication handshake on specific Windows 11 builds. This prevents the client from initiating a valid session with the host.
The Solution
The immediate fix is to roll back the faulty update on the client machine (the computer you are connecting from).
Step 1: Verify KB5074109 is Installed
Before running removal commands, confirm this specific update is the culprit.
Method A: GUI
Go to Settings > Windows Update > Update history > Uninstall updates. Look for KB5074109 in the list.
Method B: PowerShell
Open PowerShell and run:
Get-HotFix -Id KB5074109If it returns installation details, proceed to the next step.
Step 2: Uninstall the Update
You can remove the update quickly using the Windows Update Standalone Installer (wusa).
Open Command Prompt or PowerShell as Administrator and run:
wusa /uninstall /kb:5074109When prompted, confirm the removal.
Step 3: Reboot and Verify
Once the uninstallation is complete, you must reboot your machine. After the restart:
- Open Remote Desktop or Windows App.
- Attempt the connection again.
The 0x80080005 error should be gone, and the server will now correctly receive your login credentials.
Long-Term Fix and Conclusion
Staying unpatched is not a permanent solution. Microsoft has released a follow-up fix (look for KB5077744 or a newer cumulative update) to address this specific RDP sign-in failure.
Once you have restored connectivity, check for updates again to pull down the corrected patch, ensuring you don't miss out on other security fixes.