Or if you don't want to buy a product, create a shortcut on the server with this path SHUTDOWN /L /R /T:10 /Y /C - then on the other machine, map a network drive to that shourcut on the server. When you want to reboot, just double click the shortcut.
The server will reboot in 10 seconds, for a longer time change T:10 to T:30 for 20 seconds. You might want to create another shortcut to cancel the reboot too, same steps as above except the shortcut path will be SHUTDOWN /A.
To create a shortcut, right click the desktop and select New > Shortcut. Path SHUTDOWN /L /R /T:10 /Y /C click Next > Finish.
Or the easiest way...
1. Right-click My Computer and select Manage.
2. On the Action menu, press Connect to another computer ....
3. Double-click a computer in the list or enter IP address (you will need to log in when prompted)
4. Right-click Computer Management (<Name>) and press Properties.
5. On the Advanced tab, press Startup and Recovery.
6. Press the Shut Down button.
7. Select an Action:
Log off Current User
Power down (if supported)
8. Select a Force Apps Closed action and press OK.