Go to device manager (in computer management) by right-clicking on computer, select your computer (very top item in the list) and open the action menu and select "scan for hardware changes" If its plug and play it should install the hardware in the background but if not follow the onscreen directions for the wizard that appears. If this doesn't work go into your BIOS, disable your card reader, boot into XP, than re-enable it and boot into XP once more.