A lot of people have said that they have had problems with these M-Audio USB MIDI interfaces, but mine has worked flawlessly with Windows 2000, XP, and more recently, Windows 7 (although the drivers were only released in beta form very recently). I originally only used the IN/OUT-A because the Roland A-880 handled the rest of the devices. When I got the Roland VK-8 I’d run out of ports on the A-880 and so I plugged it into the In/Out-B ports. This works out really well because the VK-8 will actually respond on several MIDI channels as a multi-timbral device.