How to fix User Profile Service Failed the login Error
1.Boot computer with safe mode with F8
2.type in run as “regedit"
3.run as administrator
4.HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
If you have two folders
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. To do this, follow these steps:
5
Right-click the folder without .bak
Right-click the folder without .bak, and then click Rename. Type .ba, and then press ENTER.
10
Right-click the folder that is named .bak
Right-click the folder that is named .bak, and then click Rename. Remove .bak at the end of the folder name, and then press ENTER
11
Right-click the folder that is named .ba
Right-click the folder that is named .ba, and then click Rename. Change the .ba to .bak at the end of the folder name, and then press ENTER.
12
If you have only one folder starting with S-1-5
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.
13
Click the folder without .bak
Click the folder without .bak in the details pane, double-click RefCount, type 0, and then click OK.
14
Click the folder without .bak, in the details pane, double-click State
Click the folder without .bak, in the details pane, double-click State, type 0, and then click OK.
15
Close Registry Editor.
16
Restart the computer.
