Very rarely, Windows will refuse to allow a valid user profile to log in and give the error “The User Profile Service failed the logon. User profile cannot be loaded.”
Microsoft Knowledge Base artice 947215 describes three methods for resolving this problem. Methods 2 and 3 involve simply creating a new user profile, thus sidestepping the original problem, and need only be performed if Method 1 fails to resolve it.
In practice, Method 1 usually works, and is detailed in the Procedure section below.
- Click the Start button, type regedit in the Search box, and then press Enter.
- In Registry Editor, locate and then click the following registry subkey:
- In the navigation pane, locate the folder that begins with S-1-5 (SID key) followed by a long number.
- Click each S-1-5 folder, locate the ProfileImagePath entry in the details pane, and then double-click to make sure that this is the user account profile that has the error.
- If you have two folders starting with S-1-5 followed by some long numbers and one of them ended with .bak, you have to rename the .bak folder. The KB article shows changing .bak to simply .ba
- If you have only one folder starting with S-1-5 that is followed by long numbers and ends with .bak, right-click the folder and then click Rename. Remove .bak at the end of the folder name, and then press Enter.
- Click the folder without .bak in the details pane, double-click RefCount, type 0, and then click OK.
- Click the folder without .bak, in the details pane, double-click State, type 0, and then click OK.
- Close Registry Editor, restart the computer, and log on again with your account.
This method may not correct the error in all situations. If it does not, it will be necessary to create a new user profile and copy the files from the old, damaged profile into the new one.