Symptom 10:

You know that your system should fully support USB devices. This problem can .occur when you install a new USB keyboard while your computer is off, and your computer is set up to have you log on when you start it. USB keyboards are not enumerated until after you log on your computer. To correct this problem, click Cancel when you are prompted to log on, click Start, click Log Off, click Yes, and then log on to your computer.