All files from the manufacturer's installation mini-CD...includes drivers and a mouse properties setup utility for setting up all features (up to 5 buttons...even a zoom magnification function). I have it installed in Windows 2000, but there are also drivers for Windows 9X and NT4. It will probably work for Windows XP as well. If you use the center button (depress the mini-trackball) and it reverses normal mouse functions with the scrollwheel, then unplug the mouse and plug it back in. I think this is just an issue with my ancient mobo though.