help installing harddrives

[kaitokid]

Okay, I have a 40 gig harddrive I wanted to add to my pc, when I plug the wires in, I put the slave in first, the little one in last. But when I boot up my pc it says "Detecting IDE Drives" then about 30 seconds it goes to "Primary Drive: SD...." it stay stuck there. but when I switch the 40 gig harddrive with the 10 gig harddrive, it works! wow doesn't my 40 gig harddrive work? I want to install that one. Please help

 

[GPOCharles]

Do you have the jumpers on the Drives set correctly?

 

[kaitokid]

Where are the jumpers located? I don't see one, my master doesn't have a jumper.