It would need a custom driver. Here is the one for the SIXAXIS game pad, however there are issues with unsigned drivers like having to select the 'use unsigned drivers' option from boot up. http://news.filefront.com/how-to-use-a-ps3-controller-on-a-pc/

Sony seems to have issues with using their hardware on other systems so you wont ever find a legit driver.

I'm still interested in the real answer to this question, but in the end, I just found a controller that works.

For anyone else who really wants to do this, keep trying different controllers until you find one that works. I recommend quality console controllers (gamecube, PS2, xbox) if you already have them, connected using USB adapters, or cheap USB gamepads from eBay.

The one that worked for me cost about $7 (bought from wholesaler xinga.com years ago but try ebay etc). It's a semi-transparent (purple) chinese knock-off of the standard PlayStation 2 dualshock controller. Windows recognises it as "PS converter", so the electronics are probably identical to USB PlayStation 2 controller adapters sold by the same company (and many/most other companies, probably).