Mapping keyboard scancodes to something else with the system registry

Learned something new today: Windows 2000 and newer (that includes Windows XP and Windows Vista) support mapping keyboard scancodes to different codes, meaning that you can effectively disable or remap keys to something else. This feature can come handy in certain special situations, but I must say I'm a bit concerned about this registry key's existence from security and system stability point of view. Since the key is at:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout

...it is perfectly possible that some malicious program would disable certain important keys. But of course, there are many other critical keys in the registry as well, so the best thing is to make sure your HKEY_LOCAL_MACHINE key is indeed secured. Vista's UAC would help here!