i've just this week bought a pc with 2 monitors and it's Windows ME. PC (generic) came standard with a built in vanilla graphics card, needed an extra AGP one and now it's all fine.
If you already have your pc, get another graphics card installed or if you are buying from new you could go ahead and get the card with built in dual monitor capability like the Matrox one.
ps found a 19" monitor at 1024x768 resolution is good - it can go to 1600x1200 if you don't mind not being to read anything!
toodlepip