Deleting User Profiles in Windows 8.1 and Windows 10:
If you have ever tried to remove a user profile the same way you did in Windows 7 or XP (C:\Users), you may have noticed that you encounter an error stating that some of the files in that profile are too long to be deleted. Using the method below, you can easily remove any unwanted/unused profiles on your Windows 8.1 or Windows 10 PCs.
1) Hit Windows Key + R to easily open the Run command
2) Type sysdm.cpl in the text box and hit Enter
3) Navigate to the Advanced Tab, and in the User Profiles group, select Settings
4) Here you will be able to see all the User Profiles on the PC. It will show you the size of the profiles, and whether they are roaming or local. To delete a profile, simply select it, and click Delete. Remember that if you only have one profile, it cannot be deleted, nor can any default profiles (built-in Administrator profile, etc.)