MY old Sony Vaio is the following: Pent. 4, 3.2, 2 GB of Ram, Windows 7 32 bit.I need to upgrade it I know.It has a Radeon X300/X550/X1050 listed as the video card. I have not opened it up to see what it is exactly. What ATI card can I replace this one with to not tax the system and play at least Bioshock I and Oblivion with? I bought this box set and have yet to try to play them. Any assistance would be appreciated. Thank you.