The O2 is class-compliant, which means that no driver is required to use it in Windows XP (Service Pack 1 or higher). Just connect it to an available USB port on your PC and enjoy!

IMPORTANT: There are two types of USB ports, USB 1.1 and USB 2.0 but they look exactly the same. The M-Audio O2 is a USB 1.1 device and needs to be connected to a USB 1.1 compatible port. Most USB 2.0 ports can operate in USB 1.1 mode, but sometimes it is necessary to activate this functionality in your computer's BIOS. Besides that, you need to have Windows XP Service Pack 1 (or higher) installed to allow USB 2.0 ports to operate in USB 1.1 mode. If you run into any problems, try a different USB port on your computer and/or check if the USB port you are connecting to is configured to be able to run in USB 1.1 mode. See your computer's mainboard's documentation for instructions on this.