My USB ports were having trouble connecting to hardware such as Tom Tom, iPods, etc. While trying to fix this, I clicked a button to restore the driver. The PC sent a warning and then shut down. Now, the PC is fine except none of the USBs work. This includes the mouse. Therefore I cannot use my PC at all. 
I’m hoping that your keyboard at least works so that you can do some basic troubleshooting. If not, does your computer have a PS/2 port (it’s a round port commonly used for PS/2 keyboards)? Try using a PS/2 keyboard or a buy a USB-to-PS/2 adapter if the computer has this type of port. Even if that’s not an option, there are a few steps that you can try.
The Old Disconnect the Power Trick
As technically marvelous as computers are, sometimes they respond to low-tech solutions. When devices such as USB ports fail, the computer needs a good reset to clear out any residual power in the motherboard. If you have a laptop, unplug it and take out the battery. Leave it disconnected for about five minutes. If the computer is a desktop, unplug it from the power source and keep it disconnected for about five minutes. Plug back in and reboot. Any luck?
Enable USB Support in the BIOS
It’s possible that the computer’s BIOS is no longer set to “enable USB support.” Boot up the computer and immediately start pressing the Delete key as it boots (or whichever key your computer indicates it the correct key for entering the BIOS screen). Once in the BIOS, look for the USB mouse and keyboard support section and make sure that USB support is enabled.
Safe Mode
Let’s see if your computer will boot into Safe Mode and allow you to use your keyboard and mouse. Safe Mode loads the most basic device drivers, so there’s a slight chance that you can use your keyboard and mouse. To get into Safe Mode, boot the computer and start pressing the F8 key. Pick Safe Mode with Networking (so your computer can search online for device drivers) from the list.
Once the computer is loaded, you can then go into Device Manager and troubleshoot the USB problem. Click on the USB category that has a yellow icon next to it. The yellow icon will tell you which device is acting up. You can either update the driver by clicking the Driver tab followed by Update or uninstall this item and then reboot the computer. Uninstalling devices tricks Windows into detecting new hardware and installing the appropriate device driver. Once Windows installs new drivers, you need to reboot the computer to allow the update to take place.
System Restore
Assuming that you can use a PS/2 keyboard, the easiest thing to try is System Restore. If your computer has a restore point from before the problems began, rolling the system back in time will solve your problem! If your mouse won’t work but you have access to a PS/2 keyboard, you’ll need to use keyboard commands rather than the traditional clicking your way to Start? Programs > Accessories> System Tools > System Restore. The easiest way in this situation is to boot up into Safe Mode with Command Prompt. Once you have a command prompt, type in the following command: %systemroot%\system32\restore\rstrui.exe
Pick a restore point from just before the problems began and follow the prompts. Once restored, you’ll need to update your operating system and reinstall any programs or hardware added since that point in time. Your data files are not affected by this process.
I would try the “old disconnect the power” trick and System Restore options first.
