You can record the audio that is part of the Powerpoint presentation. By default the Audio input is set to 'Microphone'. 'You have to setup the audio input to either the Mono Mix, Stereo Mix or the Line-in option, depending upon the system configuration you have. Try experimenting a bit with these three options to find out which works the best for you. Please refer to My Screen Recorder's article that discusses the entire process: https://www.deskshare.com/resources/articles/msr_convert_powerpoint_fordistribution.aspx