asus m2n32 sli deluxe

[EVE COCOON]

Hello, I am new hereabouts, and it wanted to ask for help them ......

Each one buys me the asus m2n32 deluxe, with 4gb of memory ram, the ocz of 2gb, also the xfx geforce buys 7950 gx2 of 1gb....

With this equipment, which operative system they recommend to me to install, thank you, I wait for answers.

In this moment I have installed windows xp (64 bit)...

[EVE COCOON]

And I have a problem, only it detects me 512mb of video, and the card of video is of 1gb of video, to which this problem owes.....
I wait for his help, but it will continue reading, for answers. Thank you another time.