If Windows Vista is running in audit mode, the NUM LOCK key on a Windows Vista-based portable computer is always on.

You experience this problem in either of the following scenarios.
Scenario 1
You perform an unattended installation of Windows Vista that comes up in audit mode.
Scenario 2
When you run the Out Of Box Experience (OOBE) Wizard in Windows Vista, you press CTRL+SHIFT+F3 to try to enter audit mode.

Note: The problem that the NUM LOCK key is always on occurs because the letter keys are overlaid with the number pad.