Hi,
There is a command line tool that comes with Windows Server 2008 -- so you don't need any 3rd party or resource kit tools.
You can simply put something like this into batch file:
shutdown -r -t 60
-r is for reboot
-t is in how many seconds (60 seconds)
Name the batch file something like "reboot.bat". Now set up schedule just like you would for any other task and call that batch file at convenient time.
Regards,
Faraz H. Khan