Agree with what was said above, building pc's is not really that hard, but if your building up a gaming system, it just takes a little research to find the parts that work together the best.
My system is:
AMD quad 2.2ghz
4 gig ram
XFX ATI 5770 1 gig card
Win 7 32 bit
As for my system, it's a fairly recent install of Win 7, I don't have a whole lot installed, so it's not a background program causing high CPU. Idle cpu usage is very low. I replaced my 9800 GTX+ card with this XFX ATI 5770 1 gig card because I was maxed out on GPU before that, that happened over a year ago. I've got friends with the identical ATI card who are not having the problems I'm seeing, so I'm pretty sure it's something in the system itself. The odd thing is that I don't have trouble with any other games......perhaps it just cruddy BF3 code, but I AM crashing a lot more than the friends I play with.
I'm not having trouble with game play, just freezing, crashing, loading....another reason that leads me to believe I've got a deeper hardware issue.
Oh....and if your trying to setup eyefinity and don't have a display port monitor, you will need a active adapter, not a passive one to make it work. I found that out last night after some digging on the net.