In the Game tab, top left of the screen will say 'Remote'.
Click on Remote and change it to Free Aspect or whatever fits your screen.
Alternatively, locate you SteamVR Folder within the Steam directory. Change the 'SteamVR' folders name to 'SteamVR1'. This will trick your computer to think SteamVR does not exist. To launch VR again, change the name back to 'SteamVR'