USB device not recognized in Windows XP

I have 4 USB ports in my system, 2 in front side and 2 in back side. But the USB ports in front side are not working.
A message pops up saying that
One of the USB devices attached to this computer has malfunctioned, and windows does not recognize it.
Please any one give me solution of this problem.

USB Device Not Recognized
One of the USB devices attached to this computer has malfunctioned, and Windows does not recognize it. For assistance in solving this problem, click this message.
