Well i have been thinking about it and i really want to upgrade my OS. I have been thinking about either getting Windows Vista ultimate 64 bit upgrade disk or Windows 7 Ultimate 64 bit upgrade disk. I want to go to a 64 bit because i have a compatible processor and it can read more ram then 32 bit versions. I also want to make the change because i like to play games, more specifically Modern warfare 2 and Left for dead 2. Vista has DX10 and 7 has DX11 so i would like to get either of those two. I really dont know which one to get. Could some one tell me what they think i should get. BTW i have Xp pro now.