My situation, bought a 500 GB SATA WD (WD5000AAKS) to install on my home built machine, Mochspeed PT88AS with a gig of ram, and Windows XP Pro. I also have 2 EIDE HDDs, one of which crashed and lost its FAT that I want to pull all the data off of, and I have 2 EIDE disk drives. I physically installed the drive, no jumpers just power and data cable to the built in SATA port on the mobo. My mobo bios options are set to look for SATA before SCSI, but my bios doesn't recognize the drive, no matter what driver I try from my Mobo or any other manufacturer, I still get the yellow ! in the device manager. By pure dumb luck I did get the drive to work one time enough to use WD's lifeguard program to recognize the drive, partition and format it. After that, my drives don't show up in my computer, still the yellow ! in device manager, still not recognized by the bios, and running out of drivers to try. Suggestions?