The User Profile Service failed the logon

You receive a "The User Profile Service failed the logon” error message

When you log on to a Windows 7-based or a Windows Vista-based computer by using a temporary profile, you receive the following error message:

The User Profile Service failed the logon. User profile cannot be loaded.


Occasionally, Windows might not read your user profile correctly, such as if your anti virus software is scanning your computer while you try to log on. Before you follow the methods here, try restarting your computer and logging on with your user account again to resolve the issue. If you restart your computer and it does not resolve this issue, use the following methods to resolve this issue.

Note You must be able to log on to an administrator account to fix your user profile or copy your data to a new account. Before you resolve the issue, log on to Windows by using another account that has administrative permissions, or restart in safe mode to log on with the built-in administrator account.


Start your computer in safe mode


To fix the user account profile, follow these steps: 

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. 

1. Click Start, type regedit in the Search box, and then press ENTER.
2. In Registry Editor, locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
3. In the navigation pane, locate the folder that begins with S-1-5 (SID key) followed by a long number.
4. 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. To do this, follow these steps:
     1. Right-click the folder without .bak, and then click Rename. Type .ba, and then press ENTER.
        
        
     2. 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.
        
        
     3. 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.
        
        
   • 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.
   • 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:
     1. Right-click the folder without .bak, and then click Rename. Type .ba, and then press ENTER.
        
        
     2. 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.
        
        
     3. 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.
        
        
   • 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.
5. Double-click the folder without .bak in the details pane, double-click RefCount, type 0, and then click OK.
   
   
6. Click the folder without .bak, in the details pane, double-click State, type 0, and then click OK.
   
   
7. Close Registry Editor.
8. Restart the computer.
9. Log on again with your account.

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Nb: This error may occur if the "Do not logon users with temporary profiles" Group Policy setting is configured. 

This error may also occur if the user profile folder was deleted manually. A profile folder that is manually deleted does not remove the Security Identifier (SID) from the profile list in the registry. 

WARNING:  strongly recommend AGAINST making this the standard way to remove user profiles from computers. The documented and supported approach is by using the Advanced System Settings in the system properties, "User Profiles" settings. For programs, this is available by using the "DeleteProfile" API. 

If the SID is present, Windows will try to load the profile by using the ProfileImagePath that points to a nonexistent path. Therefore, the profile cannot be loaded.