Installing a 2nd SATA HD

I'm trying to install a 2nd 500GB SATA HD on my Windows XP system. I currently have a 500GB SATA HD installed. Here is the CPU and Motherboard: Cpu: Intel Core 2 Quad Q6600 2.4ghzX4 8MB L2 1066MHz Motherboard: ASUS P5N-E SLI Nvidia nForce 650i
I would like to set it up so I can backup the first HD to the second HD. My BIOS is set to automatically detect the HD but it does not see it. I've gone into the disk management section of Administrative Tools and it does not detect it there either. I've also use the DATA Life guard tools that came with the new HD and it says I only have one HD. The first HD is a Samsung 500GB HD and the second one is a WD 500GB HD. Any ideas?? Thanks

 

I had connection troubles with the ASUS supplied red data cables. Since your BIOS doesn't see it, that's what I suspect. To fix my issue I bought the WD SecureConnect cables.

 

I've swapped the original cable that was on my first HD, and put it on the second HD since I knew the first one worked and put the cable from the second HD on the first HD. It still only recognizes the first HD.

 

Have you've tried that drive on a different sata port? Since you've tried another cable maybe the port is bad. Do you have access to another machine you could maybe hook that drive up to just for test purposes. Maybe the drive itself is defective......

 

Looks like I have it fixed now. It was a bad power cable. Thanks everyone for the help.