http://www.serverintellect.com/support/windowsserver2003/sched-auto-reboot.aspx

shutdown.exe

just create a batch file and put the following command

Shutdown -r -f -t 0 (This is for local computer)

for network computer

Shutdown -r -f -t 0 -m \\<ipaddress>

-r = restart -s = shutdown -f = forcily -t = time in seconds -m = remote computer