Hi
fiznerpin1962, great to see you back on the game and on the forum.
6-Cores AMD and 12-Gig RAM, hey, that's a pure behemoth, great
well, coming to the core of your question, answer of which may actually be related to the "cores," or in other words, the number of the cores. As an Intel kind of guy, I'm not quite an expert on AMD CPUs like you, but just offering a guess here, I'm thinking that the game may not be responding well to the 6 cores; considering that STALKER had difficulties with 2-Core CPUs as well. Interestingly though, it performed better on Quad Cores under Windows 7. So, another set of cores may be just another step on this ladder. Have you tried to run the game on 4 Cores?
As I haven't noticed much info about the problem on your post, in regard to if it fires up then stalls, or it doesn't even respond when the exe is clicked, it's much of a guess work, but I can also recommend that you install the OpenAL from Creative Laps, if you haven't done so.
Also, if the game fires up then stalls, then you may try to play around the "lighting" options on the menu, going through the usual options of Full Dynamic Lighting, Static Lighting, and Object Dynamic Lighting.
If you could give a bit more detail on the problem, we may quite probably find a solution when we put our thinking hats