There any way to change a password on a log in screen, or something?

tl;dr, I need to get a cd to boot up without logging into windows, and f8 doesn't work.

I got a new computer, just got a ****ing keyboard for it after waiting 3 weeks, and I can't get on cuz the old owner forgot to tell me the pw. All i really need to do is reformat, but the cd drive doesn't load during bootup...

any solutions?