Have you checked the BIOS as Rvnguy suggested?
What you could try doing is a complete clear of your CMOS settings with the motherboard jumper. (Machine should be switched off at this point). After this complete reset, start up machine, go into the BIOS settings, set date, time and anything else, and check that the USB options are set to ENABLE. Reboot, go into Windows, and check Device Manager.
If still no joy, check the l.e.d. status of a flash drive when you plug it into a USB socket. If USB ports are electrically functioning but NOT enabled, then plugging in a flash drive will usually just give one quick flash of the drive's l.e.d. If the USBs are all fully functioning and ENABLED then the drive's l.e.d. will remain lit. If the l.e.d. doesn't flash or stay on, then either the socket is broken or there's a malfunction of the USB chip (or cother components) on the motherboard.
ROGER - G0AOZ.