I just looked inside my dell and seen my hard drive at the bottom where my gtx 260 is my question can i move my hard drive to the empty slot at the top for future video card upgrades like Radeon HD 5970 or 5870?
Yup, shouldn't be an issue. Just make sure that the power and SATA cables don't come loose when you move it. Otherwise, there really shouldn't be anything preventing you from moving it.