In certain rare scenarios, when connected to a system using Remote Desktop, the status of the NumLock key may go out of sync between the host and client systems. This typically can be seen on slower dial-up connections or if system resources are low on either system. Repeatedly pressing or holding down the NumLock key can cause this behavior.

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.