More info-I built my computer at an on site classe at my last employer. I tried upgrading my RAM, now my tower will not boot. I've troubleshot everything to RAM, AND CPU. Assuming problem is either RAM slot, or CPU, I was able to replace Mb and CPU. All of this because I already had 2Gigs RAM. Soooo if reuse my hard drive in Master position will my XP po, my last operating System, boot up