Hi, it happend to format my system after the format when i was installing the drivers from a USB accidently i had clicked on the Bios update patch which was stored among the drivers, the system restarted and later im not able to use any of my USb devices as its not recognised. PLS HELP!!!
try using the cmos clear jumper...also check that the onboard usb chipset is turned on in the bios. i would check to see if your mb has a flashback program or second bios. some new mb have a flash button on the back that lets you reflash the bios with the system powered off.