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.
You perform an unattended installation of Windows Vista that comes up in audit mode.
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.