You also can convert PowerPoint to video format with windows media maker.
Save the presentation as multiple images and then import them to Window Movie Maker. Then you can save it as video.
Pros:
**FREE
**No need to download other software. This tool is part of Windows operating system.
Cons:
** The transitions, animations in your original PowerPoint will not be retained.
I use Wondershare
PowerPoint to DVD converter to burn PowerPoint presentation to DVD directly with good quality!
And you also can convert PowerPoint to popular video format with multimedia files and animations.