If you are searching for a free PPT presentation to Video File Converter than WonderShare PPT2Video converter may be a good try. You can convert your Microsoft PPT, PPTX, PPS files into your favorite video format.
Wondershare PPT2Video converter has both free as well as a paid version. While the free version allows you to access only a limited set of features, these are good enough for your average needs. The free version allows you to wmv, asf, mov and mkv formats. If you want your video files converted in some other video format, then you can use some other video converter applications, some of which are freely available over Internet.
The interface is clean and simple. But you might get lots of calls for action to buy the PRO version, which might irritate some of you.