Virus

try unplugging your hard drives and cd-rom to see if it holding the mb from posting. unplug all your usb devices and plug another keyboard into the usb 2.0 port and see if the port works. you may have to find a wired keyboard.

when you reset your BIOS you probably disabled USB Compatability setting in your BIOS you will need to get a ps2 style keyboard to make it work.

If your MB has the PS2 port, then use the PS2 keyboard. (I keep the set of PS2 KB and mosue )

was extracting xp boot sectors what i had downloaded for a pc what daughter had given her, when extracted them from rar file it closed my computer down at 1st it let me on to main bios but not let me enter it, then it closed my keyboard and mouse down altogether then went to the screen which says f1 for continue or f2 load defaults but with mouse and keyboard now not working cant do either,,,,,,,i have also tried wireless, usb,and ps2 it same on them all

tried using ps2 usb and wireless it same on them all

new mb wont clear if you leave the power supply plugged into the wall outlet.unplug the mb from the wall clear the cmos..go have dinner then come back.

thankyou for taking the time to help me,i will try that soon once got the kids in bed, thanx

Do you flash the bios? If yes, then maybe you get the bios corruption.

Like smorizio said reset the cmos by removing the small button battery and wait for 10min, reboot the PC. You can get back the default BIOS configuration hopefully.

If you still can't use the PS2 keyboard/mouse that maybe time to get the new MB.