usb devices not detecting at all

hi, i have a mobo getting me so frustrated, the problem is that usb mouse and keyboard aren’t detected at all and usb flash drives are only detected in windows when i boot with it connected to the mobo, so i want to do a fresh windows installation trough usb but the usb flash drives do not detect in bios.

usb functions=enabled(but grayed out)

usb 2.0=enabled

usb legacy support=enabled

did bios reset many times

updated bios

specs

acer aspire m5630

core 2 duo e6750

3gb ram ddr2

any help is much appreciated

sorry for my english

regards

vieira gema