My HP Windows 8 laptop is running slow and won’t factory reset.

I am constantly receiving issues on my laptop. I'm not sure if its a virus because when I run my antivirus, it found nothing. But my laptop is running very slow and it shuts off pretty often. I tried to refresh and run a factory reset but it shows an error stating that there is something missing so I can't continue with the reset. I tried every possible ways to reset but I just couldn't. I really need assistance on this matter since I hardly use my laptop these days due to this issue.
