the drive is a SATA 6GBs drive and requires a SATA cable that supports SATA 6 (and it will be backward compatible if your motherboard only has SATA 3 connections).
You mention PCI EXPRESS and X1 and X16 but don't tell us why you are mentioning that as the hard drive fits in a drive bay and not in a card slot so whether you have PCI Express or not is immaterial..
Do you mean that you have also purchased a SATA 6 Host card for attaching your hard drive? If so we would need to know the manufacturer and model number of that SATA host card.
I have purchased an internal drive for my desktop. I now need the correct cable to connect to my microprocessor. The drive is a WD7502aaex 750GB.
It is PCI Express, but the retailer does not state whether it is 32 or 64 bit (my processor is 64). I have searched extensively for this information, to no avail. I have x1 and 16 slots availble according to the HP website.
I do not know where to turn from here. This was a bare drive, with no accessories.
Any assistance would be appreciated. Considering my lack of computer knowledge, I will confine all future threads to this location.