tomlikesguitar :
Okay, a few more questions that I hopefully don't look too dumb for asking:
1. why is that double jeopardy?
2. can I just get 64 bit without changing hardware?
3. can you suggest some memory? should I just buy the exact same memory for compatibility?
4. can you suggest a CPU? I'm on a budget and I always end up sucking at balancing price and processing power...
I'll address these:
1) Your CPU likely won't hold you back in this game. Most games are not optimized for quad cores, but we really don't know much about Skyrim, other than it will be a beautiful looking game on the PC, provided you have a decent video card. Overclocking this CPU higher may not be harmful, but is it feasible? I've never heard of an Athlon II hitting 4 GHz, but I suppose anything is possible.
2) Yes you can install 64 bit OS. It will NOT help you with this game other than instead of having 3 GB of ram accessible, you will have all 4 GB available. You can get 4 more gigs of ram if you like, but I doubt you would see any perceivable difference in performance. Let me rephrase that, there won't be a significant difference!
3) Yes, buy the same exact memory unless you find a steal on an 8 GB kit that would be better (faster, better timings, etc.) 8 gigs of memory will be useless with a 32 bit OS.
4 CPU suggestions would be very motherboard dependent. The Biostar board is an AM3 it appears, so if you were really worried about maxing the game out, or for other purposes (general computing, multitasking), then the only CPU you should really be looking at is the X4 955BE. Bump voltage to 1.4V, set multi to 18X and enjoy your 3.6Ghz quad core.