HI, I have just discovered all my USB ports aren't working. Does anyone know why this could be. I do use a USB mouse so I am guessing it is that. Is there anyway of fixing the problem?
Thanks
Charl

Just update the usb 2.0 drivers and restart the system

You may have USB 1.1 while your USB devices need the high-speed USB 2.0

So yeah, just install new device drivers, and maybe blow compressed air into the ports the get rid of the dust. It could be some dust build up also.

Did this mouse work before?

Any changes that either happened or that you perhaps made to your computer around the time that the problem started; particularly any Software or Hardware that you installed or setup.

What OS?

Have you tried any other devices in USB's to see if they work?

Check device mgr for any yellow marks present, if so, where and for what?
-right click on My Computer and go to properties and then the Hardware Tab and Device mgr