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

Question

I have one Admin profile (me)  and 1 guest profile (Guest)
I have followed the instructions in Microsoft KB 947215 
In step 4 it says to locate the S-1-5 folders, which I have done, find the two matching file numbers and change the .bak/ba extensions. Problem is I have 4 folders and I am not sure which to rename. If I try to add the .ba extension on the file named
S-1-5-21-803116559-3522019405-271708535-1001 I receive an error :
The Registry Editor cannot rename S-1-5-21-803116559-3522019405-271708535-1001. Error while renaming key.
Have I picked the wrong file to rename? Please advise. Hopefully I have provided sufficient information. If not please advise.
Here is a list of the folders, and their respective ProfileImagePath and State information:
S-1-5-18
 = Value name: ProfileImagePath Value data: %systemroot%\system32\config\systemprofile
        = Value name: State Value data: 0
S-1-5-19
 = Value name: ProfileImagePath Value data: C:\Windows\ServiceProfiles\LocalService
        = Value name: State Value data: 0
S-1-5-20
 = Value name: ProfileImagePath Value data: C:\Windows\ServiceProfiles\NetworkService
        = Value name: State Value data: 0
S-1-5-21-803116559-3522019405-271708535-1000
 = Value name: ProfileImagePath Value data:C:\Users\UpdatusUser
        = Value name: State Value data: 0
S-1-5-21-803116559-3522019405-271708535-1001
 = Value name: ProfileImagePath Value data:C:\Users\TEMP
        HAS NO STATE INFO
S-1-5-21-803116559-3522019405-271708535-1001.bak
 = Value name: ProfileImagePath Value data:C:\Users\me
        = Value name: State Value data: 8000
S-1-5-21-803116559-3522019405-271708535-501
 = Value name: ProfileImagePath Value data:C:\Users\Guest
        = Value name: State Value data: 80

Answer 1

Hi,
If you want to modify the registry, you must have administrator privilege.
Since no other administrator account in your computer, you may have to active the built-in administrator account.
For detail steps, please refer to the similar thread.
I receive error message: The user profile service failed the logon. User profile cannot be loaded
http://answers.microsoft.com/en-us/windows/forum/windows_7-security/i-receive-error-message-the-user-profile-service/38844b82-a2c1-4fa2-9802-a5318d6f7831?auth=1
Regards,
Ada Liu
TechNet Community Support