Device Manager Restriction

I have got a webcamera installed on my system and the
webcamera itself is mounted onto the monitor i cant really
remove it. My brother has figured out how to get into the
device manager and enable it unfortunatly and i dont want
him using it he does some dodgy stuff with it aye. . .

anyway can someone please give me some help with either,
passwording his access to the device manager, or blocking
it off completly, i want to avoid uninstalling the driver
completely
My operating system is Windows XP Home Edition
Any help appriciated. thanks
Ice

Device Manager Restriction