Reduce the size of an output file of Windows Movie Maker
First of all, you need to understand that reducing the size of the output file may reduce the video quality. If you can accept it, let me show you how to operate it.
Step1：Export your video
Step2: You can select formats and devices. Different formats and devices correspond to different video sizes.
Step3: click “Settings” to choose quality of the video, The worse the video quality, the smaller the video size.
Step4: click “Export”.