http://www.everythingusb.com/usb2/faq.htm
"the only way to see if your computer has usb 2 as compared to 1.1 is plug it in... if the drive doesn't work or if it only has a max speed of 4x then you do have usb 1.1 and you would need to get an add-on card that does have usb 2, or buy a new computer/motherboard that has usb 2"