It will be used, too be honest it wouldn't be much use with graphics cards anyway.
Graphics cards can have a throughput speed of 30Gb's your lucky to get 4Gb's from RAM (If I remembered my A+ correctly).
Why 32bit version!... 32 bit processors can only use up to 2G of RAM. I also bought 4 pieces of Corsair 1Ghz FSB speed memory and it turned out a piece was bad. And of course, my computer is a 64 bit machine that was running XP/64 and even though 4Gig is there, the computer will only tell you that there's 3Gig on the My Computer/System Properties/General Tab
Lol theirs a lot of funny comments out thier.
But yeah seems that Vista is limited to 3.5GB's.
Everyones explinations are all over the place though confusing.