I've got a Windows 2003 server that's at my remote data center. This morning I tried to connect to it via RDP, but the connection fails with the following error:

This computer can't connect to the remote computer. Try connecting again. If the problem continues, contact the owner of the remote computer or your network administrator.

I have also trying issuing a remote shutdown/restart command using the "shutdown -i" command from my local system. No error is reported, however the system does not reboot.

This server runs SQL Server 2005 and it is still fully operational and responsive to queries.

I can also remotely connect to the services control panel of the remote system.

Is there anything that I can try to regain control of the system, short of having an operator in the data center do a hard reboot on the server for me?