Many Windows Home Server (WHS) users use their machines as remote desktop gateways. Although remote desktop connection is functionally great, one annoyance sometimes rears its ugly head, the inability to reboot or shutdown a PC through RDC. Here is a screenshot of what this looks like:
Luckily there is a simple solution. First, launch cmd.exe (you can type cmd in that search box depicted above). Next, type (without quotes) either “shutdown -f” or “shutdown -r -f” to shutdown and reboot (restart) respectively.
If this is a common issue. you can always make a batch file with the above commands to give either double-click or start menu/ windows menu access to shutdown and reboot over RDC.
Update 13 March 2010: As an update to some comments saying one can just hit the Windows Security button (depicted above), the reason I did this via command line was because this is what I saw when hitting the Windows Security button: