A few hours ago I shut down PC and unplugged it to go take a nap.

Well coming back on and rebooting I noticed my screen login was changed to HFGHN GHNHN.

Update: As I was running Norton Security scan my screen went black/blueish so I just unplugged it again. 

Any suggestions on what to do? Should I just do a full system repair (delete files, etc) 

What can they do with my PC if my computer was off and unplugged? I’m sure it doesn’t matter because obviously there was access while it was shutoff, etc. 

Thanks for reading and future input!

Edit: there’s not much data anyways on there as  I reset it recently (not virus related) lol

Get a Reset, its the quickest and most safest way. Only problem is you may lose logins.

just reinstall windows smh

adwclear to start.

what is your latest download?

as lain said just reinstall