Unless you are running out of storage space, your 80 gig drive is probably adequate as far as speed goes. It will likely run at 7200 rpm. It sounds as if you have RAMBUS memory which is not so readily available and a bit costly. 512 megs is not too small even for XP in everyday use. I wouldn't put money into that. As far as wiping out your drive, you can either format it, remove all partitions or use a diagnostic utility from the manufacturer to do a destructive test and write zeros to the drive. Such is how I would prepare a disk for a fresh installation. Now, are you going to install the same OS or another? Once the drive is erases, it should be easy enough to boot from a CD ROM and do the complete operation from the disk.
I have a Dell Dimension 8200 that is 3 years old. I would like to completely wipe out the hard drive and start with a new slate. Any suggestions? Should I just buy a better faster Hard Drive. The one I have installed now is a 80GB Ultra ATA/100, don't know the RPM. Also, I have 512MB PC800 RDRAM installed. Would like to upgrade this as well. Is this hard to do? Any help would be greatly appreciated! Thanks!