…How’s that for good grammar?
Anyway, this error popped up for me in Windows 7 the other day. After the computer boots up, you click on your user icon, type in your password, and BAM! “The User Profile Service service failed the logon. User profile cannot be loaded.” And then you are logged off, and stuck back at the user select screen.
If you’re having this problem, hopefully you have another account on the computer that you can sign in to. To fix it…
- Sign into another Windows account.
- Run the registry editor.
- Navigate to HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList.
- Look at the sub-keys here in the form of S-1-5-21-XXXXXXXXXX-XXXXXXXXXX-XXXXXXXXXX-XXXX.
- One of them is probably duplicated with the extension “.bak.” Remove (or backup) the one without the .bak, and then rename the remaining one, removing the .bak extension.
- Log out and try to log in as your troublesome user. Should be fixed now!
Now, why did this happen in the first place? I think it has something to do with Windows Backup creating a backup copy of the profile during the backup procedure, and then being interrupted or something and not restoring things to how they used to be. Maybe there are other scenarios that can cause this problem as well. In any case, I hope this helps someone!
By the way, while this happened to me on Windows 7, I understand that the error can occur on Windows Vista as well.
Update: April 26, 2010
Some commenters have noted that if you only have one account on your computer, you may still be able to use this trick to fix your problem. Try booting in safe mode (press F8 at boot). If you can log in using safe mode, fix the registry as described above, and then reboot into normal mode and you should be all set.
Update: September 1, 2010
If you do not know how to use the registry editor, or you do not know how to start your computer in safe mode, Google up a tutorial for either of these and once you figure them out, you should be able to use this information to solve your problem. Or, get a more experienced techy friend to look at your computer and point him or her to this article. Explaining these is beyond the scope of this article and I won’t be posting any more detailed step-by-step in response to comments.
Update: December 1, 2010
Jon Hege reports in the comments that this problem may also be caused by a missing C:\Users\Default folder. In this case, you may be able to copy the folder over from another machine to correct the issue.