XRDP can be used to allow a remote desktop connection from a windows PC.Display Resolution

Install XRDP from the RPi command line  

sudo apt-get install xrdp

Then to use it press the windows start button > All programs > Accessories > Remote desktop connection.  Enter your IP address and then the standard RPi login when prompted and you'll get a full size grey screen followed by the GUI.

Switching between full screen and window mode in remote desktop

Use CTRL+ALT+Break to toggle