Wont let me reset

[Seldom Pro]

I have a windows 10 desktop. I tried to factory reset and delete all files and reinstall windows 10. It starts the reset and gets to 31% then stops and says undoing changes. Why does it do this. How do I fix this. I want to reset my pc and clean it up so I can keep it and not have it be so slow

 

[Colif]

Download the Windows 10 media creation tool and use it to make a win 10 installer on USB

If reset doesn't work, I would suggest a fresh install
change boot order in BIOS so USB is first, hdd second
boot from installer
follow this guide: http://www.tenforums.com/tutorials/1950-windows-10-clean-install.html

when you reach screen asking for licence, click "I don't have a key" and win 10 will continue to install and reactivate once finished

On the screen where you choose where to install win 10, if it gives you an error about GPT drives, delete all the partitions on the hdd and press next. If it still gives error, cancel out of the installer and restart PC and start installer again, it will accept next on that screen this time (some PC just need a restart here)