It would probably be quite difficult to get a card that wouldn't support 2 monitors - It's a fairly standard feature among cards since the Geforce4 days at least.
Often they'll have one standard VGA output, and one DVI (digital connection for LCDs etc), but there's a simple adapter that allows a normal CRT to be connected to the DVI.
XP Home should work fine (Windows 98 had native dual screen support!)
To get dual monitors working:
Install the card & install the drivers;
Load windows;
Right-click desktop, choose properties, choose 'Settings' tab;
There should be an image with 2 monitors in it. click the one labelled '2', and then click the little box labelled 'Extend my windows desktop onto this monitor';
Click 'Apply' and the other screen should come to life! That simple.
You can now simply drag the screens around in the little box until they reflect the physical layout of the screens on your desk.
Dual screens is fantastic. Have 2 screens at work and it really makes life easier
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