After reading this you will be able to sort an error with User Profile service in Windows 7 & Windows Vista. The error says “ The User Profile Service failed the logon, User Profile cannot be loaded”.

This error might occur when you are using a temporary user profile for logon. This error can also occur if you are switching users. Another cause of this error resides with a corruption in user profiles. Some malicious software programs can also cause this type of corruption with User profiles.

Follow the methods mentioned below to rectify these issues :

  • System Restore
  • Click Start button –> type regedit in the Search box and then press Enter.
  • In Registry Editor, locate and then click the following registry subkey:HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindows NTCurrentVersionProfileList
  • 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.
  • registry1
  • 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 .bakfolder. 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 .bakfolder. 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.
  • Double-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.
  • Log on again with your account.
  • Method 3
  • fixit

Source of this article : Microsoft Support KB