I got this to connect a PS2 controller to my PC, running Windows 8.1 x64. Plug and play did not work, and after experimenting with different drivers I found MotionInJoy, which makes it work perfectly. If you need instructions on how to set up MotionInJoy, follow this link to How-To Geek: http://goo.gl/i1zdGB (it says PS3 in the title, but there is a PS2 option in the program).
Edit: Well.. it stopped working after two weeks. "Device not recognised"