Yeah, the USB2 drivers were installed with Windows XP SP1 update. USB2 is acknowledged in the Device Manager where it says "USB Enhanced Host Controller".
I took a screenshot from SiSoft Sandra. It says that the USB version is 2.0 and that the speed is at full. I don't get it though since the speed is listed as 12mbps, which is the max speed for a USB1 port. A USB2 port, as I understand, runs at 480mbps.