in the bios is it there? also in the bios is it set to auto for both the primary and secondary channels? make sure they are both on auto. also make sure the jumpers are correct on the drive and on the other devices on that channle.
also when you turn the computer on have your hand on the drive some how if you can and see if you can feel it spin up. if not then power problem or dead drive. if it does spin up. better chance it is a config problem
once bios is set, right click on the my computer icon. then properties, once you are in that window click on the hardware tab at the top. then there is a button called device manager. go in there, once in there you should see a secton called disk drives. expand it and see how many are in there.
and im sorry if i am confising i have been up for 37 hours so far