i presume ur usb comes together with your motherboard and not
and external usb card? and u are using windows xp?
then in such a case, go to the device manager. u can find it by
typing this in ur run command: devmgmt.msc
nxt, check for any hardware in the device manager for any yellow
question marks. for those with the signs, right click on the
hardware icon and select properties.
under the driver tab, click update driver. you should see the
hardware update wizard. when asked whether to connect to windows
update, select no and then next.
now insert the driver cd that comes together with your motherboard
and select the option intall the software automatically. click
next.
now ur problem should be solved.. if not, reply again.. 
