if its a laptop its debatable whether its usefull so you could probably disable it there too.
However in the eventuallity you dont want to do that you could try this reg file:
Windows Registry Editor Version 5.00
import that and reboot, hibernate and wake up and see if its still missing. if it is the only other work around I can think of would be to hit ctrl+shift+esc to get task manager up, kill all instances of explorer.exe in the process list, then file > new task and type explorer.exe in that box.
and wait for someone else to come up with a solution