[The Skeptic]

If you reformatted and the computer keeps crashing then I am afraid that the USB hub which is part of the computer is damaged.

1: Try to borrow another USB device and plug into the computer. This is very important to diagnose the problem.

2: Try to reset the BIOS. Follow these instructions:

disconnect the power cable from the back of the computer. Open the side cover and carefully take out the cmos battery (looks like a silvery button). Keep it out for about 15 minutes. Reinstall in the reverse order and reboot. You will probably get a checksome error. If you do, enter BIOS by pressing del or F2 repeatedly when starting the computer until BIOS tables show up. Set time and date, save the new values and let the computer boot. There are computers in which other keys have to be used to enter BIOS. You can find the correct key when looking at the screen right after pressing the start button. Look for what key you have to press to enter setup.

If the computer fails after that then I am afraid that the motherboard is finished.