Help with WD SATA2 Hard Drive

I can't get my rig to see my new WD 250GB SATA2 hard drive. I am already using an 80GB seagate SATA as my master drive.

System info:

AMD 64 2800
Asus A8V Mobo
ATI 2800 Pro 256

Please Help!

Thanks.

 

Check connections such as Sata cable and Power cable

 

System Info:
AMD 64 3700+
Giga-byte Mobo
PCI-e EVGA 128 Mgs
two Western Digital HDD(sataII) 200 and 250 Gbs
! Gbs corsair dual channel memory
DVD Reader(Lite On) DVD burner(Benq 1655).
Ok I am interfiring with your tread, but same happen to me, and I had to go to computer management and initialize the drive, then partition it and format as basic, It was then recognize by windows, but windows allow only the PIO mode transfer, and not the Ultra DMA 6 that SATA is suppose to use, I am trying to find the real cure, and My first drive(OS and programs IN) Its working very good( also a sata II. hope somebody comes with a nice solution. Thank everybody