Hard Drive Not Detected At all, Lost Partition?

[FreddieTheRobot]

Recently, my hard drive went corrupt, and I couldn't even boot my computer. I installed a new hard drive, and put the second one in as a slave to see if I could recover the files, but the old hard drive isn't being detected at all. Am I doing anything wrong, is there something else I need to do? Recovering these files is extremely important.

 

[nhasian]

if both IDE drives are on the same cable, one must be set to Master, while the other is set to Slave. if both are on separate cables, they must both be set to Master or Single. Some models have a different jumper position for Single than Master.