Windows Vista Business & Remote Desktop

Receive an error message after 8 updates last night and attempt to use Remote Desktop.
The application after entering IP address of a server and click ok and recieve message stating the the DEP needs to be changed in order to use Remote Desktop. Tried to make the change and receive message stating DEP must be enabled in order to use remote desktop. The updates and Symantec Corp Ed 10.2 were installed prior to this message.