Dual Processing Processor Affinity Question...

Well, ive had this computer built for a while and its a Tyan board with dual processors. I just mainly used it for work stuff and browsing the web. Its got two processors in it but their not exactly the same. One is a 600B PIII and the other is a 533B PIII. I had two P3 533B in it but one of them went bad (die was crushed) so i put the 600 one in it. Now its running as dual 600B processors but really the 533 one is overclocked i guess.

I dont know much about dual processing but it worked fine till i found out that i cant run any games on this at all. I put in it a GeForce4 MX 460 and when i run simple 3d stuff like Windows XP 3D Screensaver the 3d image flickers and just jumps all over the place. Shortly after that a friend of mine told me that it needs to be run on one processor and one only. Knowing that and not knowing how to do it i read on it a bit more and found out how to set processor affinity. Which works great for the screen saver cause i can set processor affinity while its running but most games that i want to run i cant get into the Task Manager and set the processor affinity. Therefor my question is this:

Is there a program or a way for me to set processor affinity for certain applications before i start them so when i do start them they run on a specific processor by default?

If there is such a thing please enlighten me with a link or a response as how to. I want to make this machine useful... right now i cant even run The Sims or other simple applications that dont support SMP or Dual Processing.

Thanks

Alain Desjardins