“User Profile Service service failed the logon. User profile cannot be loaded.” error
This is a common error in Windows 7 and Windows Vista.
Here is the solution.
1. You have to boot into Save Mode by tapping F8 key during the computer start-up.
2. In Start in the search field write regedit
3. When you open regedit find the following directory
4. There is directory for each user. If there are two directories with exact same name and one has a “.bak” at the end of the directory name, here is your problem.
5. It’s easy to solve. You have to delete the directory WITHOUT!!! the .bak at the end /red one in the example above/.
6. Then rename the other /the green one/with removing just the “.bak” from the end.
7. Close regedit, restart and try to login
If you are unsure of what you have to do, check this video :