I have an E-machines (I know they suck, but they're cheap) with an Athlon XP 2000 and 512 MB of ram. I installed a WD 120 GB hard drive and it works fine. I tried to install the old 80 GB hard drive that came with the computer and when i hook it up as a slave drive i get an error saying no OS found. I unhook the 2nd drive and turn it on and it works. What gives? If i unhook the new one and use the old one it works fine. I am running windows xp home and am completely frustrated. can anyone give me some ideas?