I have a Dell Latitude D400 (No CD ROM Drive) and No Hard Drive. I bought a hard drive (WD 60 GB) and used a Laptop to Desktop Hard Drive adapter and installed XP Pro on my Dell OptiPlex GX100 (PIII-866, 256 MB RAM), which definately meets the requirements of XP. It installed fine and I was able to use the hard drive on the OptiPlex. I removed the HDD and placed in the D400. I poiwered it on, and... received the blue screen of death (A problem has been detected and Windows has been shut down...) I placed the hard drive in a Dell Dimension L866r and it worked. I tried another hard drive (Toshiba 20GB) and received the blue screen of death. The Toshiba drive I tried a while ago on an Inspiron 2500, and the blue screen appeared. It seems that the hard drives will work in the desktops that I have, but not in any laptop. Any ideas???