“What operating systems is this compatible with, and will it work with my HP dc7900 SFF PC? I just got a HP dc7900 PC that came without a hard drive. The stickers on the front of the computer show that the computer origionally used Vista, and it has an Intel Core 2 vPro 3.00ghz processor. It currently has 1 2gb stick of ram, but has slots for up to 3 more.”