Replace/bypass administrative password

[Glosta83]

Hi to all & really could use some help...a friend gave me his old PC that I want to fix up & give to my daughter but the problem is my friend doesn't remember his password for any of the programs installed. It has Microsoft XP along with AOL 9.0...the only way I can get online, etc..is using his son'e name/password but unable to acsess any programs to remove them. Is there a way to change the XP administrative password or just remove the whole XP program? I was thinking of replacing the whole hard drive perhaps...would that work? Totally lost as to what to do as I'm pretty much a novice but learn as I go...just to have full rein to remove & clean the thing up would help, as right now I can't even do a simple disc clean-up! Any help would be greatly appreciated..best regards, Jim