I poked around for a bit, and couldn't find this particular driver (the one that worked for me at least) or a solution to my problem, so here it is. I'm running PCSX2 on a Windows 7, and bought this gloriously cheap piece of crap to convert my Dual Shock 2 controller to a USB output. After plugging it in though, I got power to the controller, and Windows ID'd that a controller was there, but no input was being picked up. After tooling around for a bit, I found this driver, and after installation, voila, I get signal from the controller. I haven't vetted that site or the driver too thoroughly, and I would encourage anyone to back-up before installation like I did. But, it worked for me. Aaaand back to vidya.

Edit: Fixed the links.