I've decided to upgrade my PC's (4GB)Hard Drive for the first time. My plan was this, (1)Buy a new Drive and a legit copy of WinXP (2)Remove the old drive (3)Insert the new drive (and possibly a new DVDROM and Video Card) (4)Install XP on the new drive.
Recently I heard that the BIOS remembers what hardware you have on your pc to aid in startup. Should I reformat my old hard drive before installing the new one to avoid this problem, or is it even a problem at all?
The BIOS remembers what hardware you had, and checks for changes. If it finds changes it updates itself, which takes a few seconds more the first time. It's really no big deal.
I think Rramjet misread the question, there's no need to do anything to your old hard drive if you're doing a fresh install on the brand new one. Even if you're keeping it in the machine as a secondary drive, you can leave it as it is if you want with no problems.