I upgraded my optical drive a while back with a Sony NEC Optiarc CD/DVD-RW. It worked fine, and recently I put in a secondary hard drive, Seagate, 80gb IDE ATA. That also worked properly, but I decided to move it another computer & make it the primary hard drive. After I removed it & booted up my system it said 'secondary drive not detected', so I went into the Bios & put the secondary drive on off. When it booted up I noticed that the Doptiarc) drive was not there. After I finished working with the other comp I decided I didn't need it there & put the secondary drive back in the main comp and it worked properly, but the optiarc still is not detected. I looked in the Bios, in the boot sequence, & next to IDE cd drive it says, 'not installed'. The jumper settings I had when it was working was main drive on master, secondary drive on slave, & optiarc on cable. I put the both the secondary & optiarc on slave to see if it would detect it, but I got the same results. I also went to manage under my comp, and the optiarc disk is not there. How come it's not recognized now? Other spec on my comp are: Dell 8250 Pentium 4 3.06ghz HT 478 pin Phoenix Bios 512mb(2*256) RDRAM PC1066 Main hard drive: western digital 60 gb IDE ATA Secondary hard drive: seagate 80gb IDE ATA 7200rpm Optiarc is also on IDE cable. OS: XP home sp2 Any advice is appreciated, thanks.