can somebody help me..

im trying to reformat my new computer,
actually the only problem is that when the windows xp is done extracting files from the cd before starting the setup it crashes and it states about something wrong with my hard disk.. maybe caused by virus or failure to detect.

when im using the windows vista and trying to reformat the disk c: and just states that the drive c: is not ready

what should i do..
is there a problem with my hard disk..
before i take my warranty for it i want to know how to fix it because im a computer student and it would be a great experience and knowledge if i know how to fix my own computer

thank you so much!