I'm not exactly good with computers so I'm going to need some help here. I have a Dell dimension e510 and I am trying to install a 250gb western caviar hard drive. But I'm stuck and I don't know what to do. I put the hard drive into the slot but there seems to be a missing cable or something. In the picture you see a hard drive and a second one, the cable on the right is a double cable that could go into the first and second hard drive but the blue cable only goes into one slot. Am I doing something wrong? thanks.