less than 256 megs video ram?

I get the same problem. I have the C&C 3 Kane version with the latest 1.5 patch. The trainer doesn't work for me either. Pressing Shift+B or anything else doesn't work and if i alt+tab too much i get the same message and the game crashes. I own Win Vista with the game running in administrator level and i even tried running it with the XP compatibility. Can someone help me please!!!Any help is much appreciated.

Cain.