Fullscreen With VR Not Working

Hello!

I have an Oculus project packaged and i want to have the game mirrored on a PC screen whilst someone is using it. I have packaged fine, and it is mirroring, but when i hit alt+enter the game goes into rift but i cant seem to get the mirrored game to go into full screen, or even windowed mode. It seems to have fixed resolution, does anyone know how to fix this?!

Thanks