Ill have to do some research on checking bios, never have done that before, as for the drives, My 4gb was set up as the Master, and the 6gb as the slave. Both had win98 on them, and when I tried this first, I just got the start up screen for the type comp I have (emachine window before the boot screen), and that would hang for as long as it wanted, rebooted with either drive, would boot up fine. Set the 4gb as Master and a 2 gb as slave with no os or anything on it, and it detected it as secondary ide drive. Not sure why it would not detect the other hard drive as a slave, followed the jumper diagram for the clip placement per the instructions on the face of the hard drive. I now have a spare 6gb hard drive with 98 on it that I could use for a third pc, just curious about the issue at hand. Maybe the os on both are cancelling each other out?