Bought an iMac 27" and installed Windows 7 on it. However, while I am able to install games games (tried Dragon Age: Origins and Neverwinter Nights 2), I am unable to run the games because apparently I have no video memory on the computer. I ran dxdiag and the Approx. Total Memory came back as n/a. Is there any way to rectify this, it doesn't seem right. 