Location of windows automatic backup (system restore) of user profiles

First you need to boot into safe mode and then have to enable the built-in Administrator account. Incase if you are not able to boot into the built-in Administrator account in safe mode then enable the Built-in Administrator account. So after successfully enabling it, follow the below method:

1. First click on Start menu
2. In the search dialog box, type regedit and press enter
3. In regedit, go to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
4. In the left pane, look for the S-1-5 folder (SID key) with the long number that has .bak at the end of the numbers.