Windows 7 beta cant find my hard drive!!! helpp? -

I have just built a computer and it has a 1 TB 7200 RPM seagate hard drive in it. When i turned on my computer it says that there is a media connection error. When i go into BIOS it only finds my CD/DVD drive but cannot find my hard drive. When i put in the windows 7 beta CD to install it into my computer it goes through a little bit of it but when i have to select what hard drive to install it onto there is not selection for my hard drive. When i click browse and put in my motherboards (intel dp45sg) driver CD it searches the CD but says it cannot find any driver software. I need some help making my computer find the hard drive. Pleasee help out soon and thanks in advance!!

check your hard drive connectors, both ends. might have a bad cable try another one.

Check the pin alignment on the cable yo make sure they match up