GTX295 problem with Crysis

ok i have built my new desktop few days ago and i installed Crysis

when i tried to play it it was very choppy and laggy. like it was unplayable

so i googled some forums and fixed few things in nVidia Control Panel.

and i have played Crysis again and it gives me average 10~20 fps. i have no idea what the problem is. the driver is up to date

i have updated today which is 6/19/09

today i have RMA'd my GPU for replacement thought it was defective. BUT! it's for replacement the other one will be here

and i just want to make sure if im doing anything wrong.

and here's my desktop specs

(Windows Xp SP3 32bits, Personally hates Vista)
(DirectX10 Installed)

AMD Phenom II X4 955 Black Edition Deneb 3.2GHz
G.SKILL 4GB (2 x 2GB)
ASUS M4A79 Deluxe Motherboard
XCLIO GREATPOWER X14S8P4 850W
ASUS ENGTX295

Please Please give me solution for this

SORRY IF MY ENGLISH WAS BAD TO READ IM NOT AN NATIVE SPEAKER.

I dont get it why ppl RMA there products so quick. Since i doubt its the card.

Try running that card with a p4.. and youl get crappy results aswell. What i'm trying to say is we need your specs. And at what settings your playing it

I recall vista giving the 3870X2 a great performance jump back in the day, or it might have just been the upgrade to sp1, whichever... it may be the same case for that GTX 295, or any dual gpu card. But the settings and resolution you have the game at could be the problem... yes... there are possible settings that will give you 10-20 fps with a gtx295.

I don't see what the big deal is about vista, over time the majority of problems have been fixed, it is a very nice os to work with now... and xp could very well be your problem.