"The Group Policy Client service failed the sign-in. Access is denied" Error This is a fix for Windows error "The Group Policy Client service failed the sign-in. Access is denied" when a user is attempting to sign into Windows. If connecting to another computer on the network: 1. Open Registry Editor as admin 2. Click "File", then "Connect Network Registry". 3. Enter the hostname of the computer, then click "Ok". 4. Click “HKEY_USERS” under the networked computer. 5. Click “File”, then click “Load Hive”. 6. Wack out to the suspect user’s profile “Users” folder of the networked computer, such as \\D13406\c$\Users\IS90062 7. Type “NTUSER.DAT” (hidden file) into the “File name:” search bar, then click “Open”. 8. Enter any name for the “Key Name”, then click “OK”. 9. Expand HKEY_USERS, then right-click on the suspect profile’s name that you created, then click “Permissions...” 10. The suspect user should be in the list and have “Full Control” permissions. If not, click “Add” and add the user to the permissions list. Administrators and SYSTEM should both be present with Full Control. 11. Allow “Full Control” access for the suspect user, then click “OK”. 12. Click “File”, then “Unload Hive”, then click “Yes”. 13. Restart the computer to ensure the changes take effect.