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

This error may be displayed when you try to logon to the operating system. Follow the procedure below to resolve the issue:

IMPORTANT: If the error message prevents you from starting the operating system, boot the computer to Safe Mode  before continuing.

NOTE: Because each of these steps represents a possible solution to this issue, try to logon to the operating system after completing each step.

1. Follow the procedure below to edit the registry:

   WARNING: There is a risk of software corruption and data loss when editing the registry. This solution should be used only if you are an experienced Windows user. It is recommended to create a backup copy of the registry  before proceeding.

   1. Click the Start button and then in the Search box, type: regedit
   2. Press the Enter key.

      NOTE: If prompted for an administrator password or a User Account Control prompt is displayed, type the appropriate password, click Continue or click Yes.

   3. In the Registry Editor window, navigate to the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList folder.
   4. In the left pane, under the ProfileList folder, locate the folder(s) that starts with S-1-5 followed by a long string of numbers. The folder(s) is called the SID key.

      NOTE: To verify you have selected the correct user account SID key, look in the right pane next to ProfileImagePath and you will see the username.

   5. Depending on the number of SID key folders that are listed, follow one of the procedures below:
      • If you only have one SID key folder, use the following procedure:
        1. Right click on the SID key folder that has .bak on the end and then click Rename.
        2. Remove .bak from the end of the folder name and then press the Enter key.
      • If you have two SID key folders, use the following procedure:
        1. Right click the folder that does NOT have .bak at the end and then click Rename.
        2. On the end of the existing folder name, type: .bk and then press the Enter key.
        3. Right click on the SID key folder that has .bak on the end and then click Rename.
        4. Remove .bak from the end of the folder name and then press the Enter key.
        5. Right click on the SID key folder that now has .bk at the end and then click Rename.
        6. Replace .bk with .bak at the end of the folder name and then press the Enter key.
   6. In the left pane, click the SID key folder that does NOT have .bak on the end.
   7. In the right pane, right click RefCount and then click Modify.

      NOTE: If RefCount does not exist, right click a blank area in the right pane, click New and then click DWORD (32-bit Value). Type: RefCount and then press the Enter key. Skip to step 9.

   8. In the Value data: textbox, type: 0 and then press the Enter key.
   9. Right click State and then click Modify.
   10. In the Value data: textbox, type: 0 and then press the Enter key.
   11. Close the Registry Editor.
   12. Restart the computer.
2. Follow the instructions in the Microsoft KB Article ID 947215.
3. Use the System Restore feature of the bootup System Recovery options  to restore the operating system to an earlier time when the computer was operating properly.