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

Steps you can take to attempt to salvage your User Profile

  1. Regedit32
    Anyone who has used Windows OS would no doubt have seen all kinds of errors over the years. One of these errors though is a little less common, and can be difficult to deal with if you've not seen it before. This error is:

    The first thought is to hit your favourite search engine and see what tips are out there. As it happens there are quite a few posts on this error, even some YouTube videos.

    The catch though is these people are demonstrating one possible solution - which I will address here in a moment - while Signed-in to their Desktop, and in a many cases they are not using the Windows 10 OS.

    So while getting a visual demonstration is helpful, its not a lot of use if you cannot actually sign-in to your Desktop so you can try their suggestions.

    What follows is some steps you can take that may allow you to resolve this problem relatively quickly, and thus be able to Sign-in to your standard Desktop and carry on with whatever it was you wanted to do before you hit the error message.

    I cannot sign-in, so how can I get to Safe Mode?

    Scenario: You booted your computer, and swiped or clicked your lockscreen only to discover when you attempt to sign-in, you receive the error message and thus cannot sign-in.

    To address this you need to be able to modify your Registry, and this will need to be done from the Safe Mode Desktop. How do you get to Safe mode though?
    • First, you need to restart your computer to get back to the lockscreen.
    • In the bottom right corner of the lock screen you should see the Power icon
    • Left click on the Power icon
    You should see options Sleep | Shut down | Restart
    • At this point Press & hold down your SHIFT key and while held down left-click on Restart

      This will take you to a blue screen. On this screen click Troubleshoot then click Startup settings

      Finally, click the Restart button

      Your computer will now restart bringing you to another blue screen with a long list of choices.
    • Press your F4 key to allow the computer to boot to Safe Mode
    • Now see whether you can sign-in to your account in Safe mode
    Note: If your User profile is corrupt, then it is possible you may not be able to sign-in to Safe mode here either. However, for the purpose of this article I shall assume you managed to sign-in to the Safe Mode Desktop.​

    I managed to sign-in to Safe Mode Desktop. Now what?

    If you are able to sign-in to your Safe Mode Desktop, this will allow you to modify the Registry. To do this you will need to open the Registry Editor.
    • Press Windows key + R to open the Run dialog
    • In the Run dialog type regedit then click OK
    • You'll now see the Registry Editor window. In its address bar you will see the word Computer
    • Left-click inside the Address bar. This will cause a flashing cursor to appear to the right of Computer
    • Now copy & paste the following into the Address bar
    Code (Text):
    \HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList

    Press your Enter key

    Sample image


    After pressing the Enter key the left pane expands to the ProfileList key and expands its sub-keys.

    You'll see here a series of sub-keys that has names starting: S-1-5-21. The number you have here will vary depending on the number of User Accounts you have set up on your computer.

    The first one which ends with -1000 is the Default User Profile [
    Ignore this key ]

    The next two keys will likely contain the Profile you are having trouble with.

    To confirm this you want to do two things:

    1. Take a look at their names. Are they identical, with the exception one of them has .bak on the end?
    2. If the answer to question 1 is yes, then left-click on the sub-key with the name that ends with .bak This will allow you to view its content in the right pane.

      In the right-pane take a look at the ProfileImagePath and look at its Data value column. If this points to the Username of the Account you are experiencing the trouble with then this key is the one to work with, & also its sister key [ the one without .bak ]

      Sample image

    So assuming you have the correct sub-keys now, the next steps are as follows:

    • In the left pane you need to right-click on the sub-key that does not end with .bak and select Rename
    • The sub-key will appear highlighted. Left-click once then add .ba to end of its current name then click away from the sub-key to take focus off it.
    Sample image


    • Now right-click on the sub-key that does end with .bak and select Rename.
    • This will appear highlighted. Left-click once then backspace to remove the .bak and click away from the sub-key to take focus off it.
    Sample image


    • Now right-click on the sub-key ending with .ba and select Rename.
    • This will appear highlighted. Left-click once then add k to end of name and click away from the sub-key to take the focus off it.
    Sample image


    So in a series of three steps we have simply swapped the naming of the two sub-keys.

    Note: In some cases you will not see two S-1-5-21 keys that are identical, with the exception one has .bak at the end of its name. Instead, you may only see a single S-1-5-21 key with .bak at the end of its name. In this case, simply rename the key by removing the .bak from its name, then continue on to the final step below.

    The last step is to do the following:

    • Left-click on the sub-key that does not end with .bak so you can view its content in the right pane
    • Double-left-click on State in the right pane. You'll see a window pop open.
    • Check that the Data value field in this pop-up window has a 0 in it. If it does not then replace whatever is there with a 0 then click OK
    Sample image


    • Close the Registry Editor
    • Click on Start and select to Restart your computer
    All going well, you ought to now be able to sign-in to your User account.​

    Note: If you do not see any S-1-5-21 keys at all with .bak on the end of its name, close the Registry editor, and restart computer. Given you were able to sign-in to the Safe Mode Desktop there is a good chance whatever caused the error has resolved itself, meaning you may well be able to now sign-in to your normal User account with no problems.

    If you still cannot sign-in, then there are some other steps you can take, but these will be addressed in some additional articles which I'll link to when they are composed.


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