Error in Windows 10 Update When user Data Is On Second Harddrive

I described in a previous post how you can separate user data from the system disk. As already mentioned in this post, this can cause errors with updates. However, I had not anticipated issues with version upgrades within Windows 10 itself. Well, the Creator Update presented me with an issue, and here is how to solve it.

If you encounter an error with a Windows update after having separated user data from the system disk, check whether the issue is indeed related to this change:

• you most likely received "Error 0x8007001f"
• check the log file: C:\$WINDOWS.~BT\Sources\Panther\setuperr.log - you will find an entry like this: Cannot add mapping for user profile C:\Users\

If the above check indicates that you have the same issue as me, there are several options to solve it, the most obvious one being to revert the process and move the use data back to the system disk.

However, that means to move a ton of data, which may may not even fit on the system disk - after all, there had been a need to separate them in the first place. So I went for this much quicker solution:

• open Regedit
• look for the key "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList"
• Here you will find a number of sub-key that look like "S-1-5-21-You will only have to look at those keys, which are longer than just "S-1-5-18" - these represent your users, the short ones are system accounts that you do not want to touch
• Each of these keys contains a value named "ProfileImagePath", which points to the user's directory. If you followed the intructions from my previous post, the values willlook like "C:\Users\SomeUserName"
• Change each of the to point to the "real" user's direcrory, not going hrough the link on C:, for example "D:\Users\SomeUserName"
• After changing all the users (it is not good enough to just change the current one), run the Windows update again

Chances are it will work this time :-) And if not, you probably end up with an issue that is not related to having moved user profiles to the second disk. If you do indeed encounter other issues (lucky me, I did not), you may find this post helpful.


Finally, after the update you may want to go through the previous post again, as the update kills the link to the Users directory.