Restart PC via remote desktop with Explorer.exe dead
You could go into Task Manager within the remote desktop session by pressing CTRL+SHIFT+ESC.
- Click File
- Click New Task (Run...)
- Type explorer.exe and click OK
That will instantly restart the Explorer shell without the need to restart your PC.
If you can send a ctrl-alt-del to the remote computer, then you should be able to launch the task manager. From there you can click File->New Task. Launch the command prompt (cmd.exe).
From there, you can restart the computer with a 1 second delay with the following command:
shutdown /r /t 1