GTX 260 SLI horrible framerates

Ever since I got my motherboard replaced, things were buggy on my computer.

I formatted the hard drive then installed windows vista premium 32, the bios on the board was so old that it didn't even recognize my processor at first so then I had to go through updating all the bios, which took forever because the asus download couldn't fine the server. After I installed all the drivers I activated SLI on my 2 gtx 260s and played some games on it (crysis, far cry, world in conflict) and they seemed to run a lot slower than benchmark results have shown.

I installed the latest display drivers and thing like the screen going black then flashing back whenever it asks for administrative approval for something like installing a program, my screensavers don't work... ever....

My cpu is only running at 4% when Im at the desktop and only 50% in each core when I'm running crysis at very high, and it's lagging

the lag wasn't too bad until recently when I installed crysis warhead and it felt as if I was playing with 1 card (on very high)

crysis' framerates were also down from what they were. I installed an even later version of the drivers and now SLI is about 100% slower than 1 card. it's pathetic. the temps are fine too (they NEVER get above 55) ever

I have no idea what the problem is, my entire computer is just slow and I don't know why.

any suggestions.

in the end im thinking of just installing windows vista 64 bit though im not sure if my bios updates, which were mean for 32bit will not allow that.

Striker II nse
Intel e8400
GTX 260 216 SLI
2X2gb gskill 1333
corsair 750w

sounds like bad motherboard. this problem sounds a bit similar with one of my friend. his motherboard can't detect his cpu clock correctly so he checked the motherboard and he find some burned component on his mobo. the good part is the mobo still functioning but the bad part is the performance is reduce from the original. and he use that board for a few years before he replaced it.......