Tinker, do you mean that the BIOS or Windows does not detect the HDs? First step in detecting the hard drive(s) is through the BIOS 'automatic' HD settings( of course you know that). Manual settings cab be unreliable on 'some older mobos, but I know you have the new Intel mobo, so that is not a concern. What is a concern is maybe the mobo is defective! Easy way to be sure is to watch the cold boot settings. If the result is "Not Found" (depends on your BIOS manufacturer for the terminology) then I would suspect a faulty BIOS or faulty onboard IDE controller. Maybe setting the BIOS to default settings and tweaking it afterwards will find a solution. Wish I was there to experiment with it. It is possible to Flash the BIOS and sometimes a faulty Flash will setup just fine, but actually have faults. A new Flash may be in order? Now if the four HDs are the only devices on the two IDE channels then they all should be deteced by the BIOS. Do you have any other devices sharing the two channels? What about the CD-ROM drive, etc? How are they configured? I know you have them on a controller card now - but how were they configured before? But, you did the right thing in the long run, a 133 controller card is what I would use for anything with more than two HDs. Connecting the CD-ROM, CD-Writer, DVD Player, etc to the two primary IDE channels does free up some data paths and keeps it all free of congestion or bottleknecks. Controller cards can cost as little as $15.00 if you shop around and thats a small price to pay for optimal performance. Hey bro, sell em and get SCSI