1. Navigate to the Display tab  Background-Info.png

2. Click the checkbox next to Backgrounds Folder

3. Select the folder containing your new backgrounds or replace the backgrounds in the default folder using the exact file name:

C:\Program Files (x86)\PhotoBoothSolutions\SocialBooth\Assets\Backgrounds\

All backgrounds should be designed in 1920x1080 resolution. If your monitor resolution is smaller you will not be able to see the outside of the background.