ATI x600

I bought my computer in June and I have a ATI Radeon x600 hypermemory  256 video card on the system.   I recently installed Star Wars Knights of the Old Republic (the game is around 2 1/2 years old) and I am getting a warning that my video does not meet requirements.  This game used to work on my old computer and it was over 4 years old.   Is there anything I can do to make this game work on my computer.  Thanks