Ultimate Boot CD

I am new at this sorta stuff. I was attempting to format my harddrive using the disk but my power cable came out(no battery). when i turned my computer on it no longer read disc correctly. Every hd i put in is reporting in the bios as have 20 more gigs than it is supposed to have. Is there a way to get the bios back to normal without flashing it?

What kind of Computer is it? There is a way with Dell BIOS'es that if you hit ALT-F is sets back to factory defaults. Don't know about others.

As for it reporting larger than what it is... The HD utils would not overwrite or even modify the BIOS. It is a tad odd though...