typically you don't need drivers, especially on XP... but even installing the drivers it should recognize it as a device. What software are you actually using to scan? I usually use photoshop.

Btw, although photomerging will sort of get you a complete scan, from my experience things will still be off (which is not good for something that needs to be so precise). Seriously, inserts being off as much as 1/16" will mess up your layout. If your intention is to cleanup playfield art to do overlays, you are not going to be happy with the results unless you're doing small sections. It's hard enough getting a perfect full overlay to lineup without the art also being off. Using this method for scanning cabinets and backglasses sure, playfields not so much.