Problems using System Recovery

[KnightPlutonian]

I'm trying to prep my desktop for resale, but I keep running into problems when trying to reset the computer. I'm using the standard Windows Recovery "Reset this PC" option and removing all personal files, but whenever I try, it fails and gives me this error message, "There was a problem resetting your PC. No changes were made." Does anyone know how to fix this, or whether I should use a third party program to wipe my drive of everything but the operating system?

The PC was built by a friend, and I think might have originally been on a pirated version of Windows 8.1, but I updated to Windows 10 shortly after I got it. Might that be the source of the issue?

 

[rgd1101]

if it upgrade to windows 10 and activated.
just download http://www.microsoft.com/en-us/software-download/windows10 and reinstall

 

[KnightPlutonian]

It wasn't completely updated, so that might have been the problem. I'm updating right now, but I'll get back when it's updated and see if it will work afterwards.