The data in my signature is copied from Dell's packing list/invoice. Dell's online documentation lists my hard drive as "ATA-66 or ATA-100 Ultra Hard Drive" and "Hard Drive, 40G, IDE, 3.5" Form Factor, 1N, 7.2K, WD-XL40." I want to install an 80GB Hard Drive in a USB 2.0 External Enclosure. The online hard drives I am considering are all listed as Ultra ATA-100. Would this type HD be compatable with my system?