Mosaic

When using Nvidia Mosaic it is sometimes not possible to run Unity in Windowed mode, build settings are overridden by Mosaic somehow. This can, however, be fixed by editing the registry settings of the application. 

The required settings are 

Screenmanager Is Fullscreen mode_h3981298716 = 3

Screenmanager Resolution Height_h2627697771 = Window Width

Screenmanager Resolution Width_h182942802 = Window Height

Be sure to modify the Decimal value, not the Hexadecimal.