Getting into a Windows 10 PC

Hey tech support,

I recently bought a pc from my buddy that he practically gave away because he claimed there was no way to get into it as he did not have the login password. I'm usually ok with computers, so I snagged it and figured I could get in no problem. I was wrong, but i'm hoping you can help.

The PC in question is an HP pavilion notebook. It originally ran Windows 8, but has since been upgraded to Windows 10. Without the ability to boot from a thumb drive and reset the admin password as described here I am stumped. I don't want to pay 50 bucks at a repair store to take care of this, so i thought I'd try here. Also, I don't really care about windows 10, just want to get the laptop running if that makes things easier.

Thanks in advance for your help!