There are many file conversion software's and websites available online for converting your power point presentation to video formats. As a trial, these softwares and websites let you do the conversion for free but the resulting video contains their own advertisement as watermark which makes your video look unprofessional.
Earlier authorstream (a ppt sharing site) used to send high quality video version of the uploaded power point presentation in email for free, but they have also stopped this free service recently.
So is there any option left. Possibly yes as long as it's available. After lot of search I came across a software called E.M. Free PowerPoint Video Converter V3.20 (Freeware) which lets you convert your PPT to standard video formats without embedding any watermark.
You need to install the free version of this software and you can easily convert any ppt to basic video formats. The snapshot of the software is shown below:
To download the software directly use the following link: Free PPT to Video Converter