1.First Go into the BIOS and make sure Plug And Play OS is enabled or says yes
The cables for sata drives are usually quite stiff and the standard connectors don't have any locking facility. I would guess that you may have a loose connection that the application of a little electrical tape should fix
you need to be running win exp with at least sp1, preferably sp2, for hard drives larger than 137GB
Some hard drive manufacturers, such as western Digital, use a proprietary SATA cable that locks to the drive. Western Digital calls its SATA cable SecureConnect. The end of the cable that connects to the drive has a special secure connector. Read the following guide to see a drawing of the cable.
Western Digital Serial Hard Drive Installation Guide - http://www.wdc.com/en/library/sata/2779-001006.pdf
Here is a useful extract from it:
"Q: Why does Windows recognize the drive as "SCSI" when it is Serial ATA? A: Most third party controller cards and RAID adapters are recognized as a SCSI device under Device Manager. This is normal and will not affect your drive or system performance. Q: How do I verify if my Serial ATA drive is recognized by my system? A: Right-click on the My Computer icon, select Properties, left-click on the Hardware tab, and click on Device Manager in the window. Double-click on Disk Drives. Your new Western Digital Serial ATA drive should be listed as a "SCSI Disk Device" or "Serial ATA Disk Device." If not, make sure that all cables are securely attached and that your system BIOS has been properly configured."
If anything let me know