I just aquired an HP LP1965 19" monitor and was wanting to run a dual monitor setup.  Is there software that I need to purchase to accomplish this.  My specs are OCZ 700 WT power, Asus P5N-E SLI motherboard, 4GB crucial ballistix Ram, Evga 8800 GT 512 MB Video and an intel E8400 C2D processor.

I have that video card and I can go double just by plugging in the second monitor make sure you set it in the nvidia control panel tho or its going to mess up your computer ^^ i learned that the hard way.

just right click on properties and the monitor utility loads or vista go to personalize.
 
you see a picture of 2 monitors in xp, you clock on one or the other to set the priority and resolution
 
no software is needed, its all in the os already