Reboot the local machine now:

shutdown -r -t 0

Shutdown now showing a dialog box with a timer (in seconds):

shutdown -s -t 60

With a timer and a message:

shutdown -s -t 120 -c "Please save your work immediately because the server is being rebooted!"

Shutdown another computer in your domain:

shutdown -s -m \\computername -t 10

Cancel a shutdown:

shutdown -a

Download and extract the PsTools package from SysInternals (now Microsoft). We extract the zip archive into C:\Support\PsTools\ as a convention.

Use the 'at' command to schedule a one-off reboot:

at 2:00am c:\support\pstools\psshutdown.exe -r -f -c -t 10

or shutdown:

at 2:00am c:\support\pstools\psshutdown.exe -s -f -c -t 10

Where:

-s: Shutdown windows server
-r: Reboot windows server
-f: Forces all running application to exit
-c: Allow the shutdown to be canceled user
-t: Specifies the countdown in seconds until the shutdown

http://www.itbox4vn.com/2011/05/how-to-schedule-windows-server-20032008.html

http://www.wegotserved.com/2011/11/04/set-automatic-scheduled-reboots-windows-home-server-2011/

Task Scheduler → Action → Create Task → General

1. Name the task “Reboot”
2. Use the following user account “SYSTEM”
3. Select “Run with highest privileges”
4. Configure for “Windows 2008 R2”

Task Scheduler → Action → Create Task → Actions

1. Set the Action to Start a program
2. Set the Program to C:\Windows\System32\shutdown.exe
3. Set the Arguments to /r /f /t 300 /c “This Server will restart in 5 minutes. Save and Exit NOW!” /d p:4:1
4. Set Start in to c:\windows\system32