Click the button located in the top right corner. Click the three dots (...) button to browse your files.

stands for DirectX Control Panel . It is a tiny utility that allows you to manipulate how the Direct3D runtime behaves on your system. Specifically, it allows you to force the DirectX 11 runtime to ignore the DWM manipulation.

Click . Do not close the Dxcpl window. Simply minimize it. (The settings persist after closure, but keeping it open allows quick debugging).