I wonder if you have really asked the right question. Do you just need to put
the presentations on a DVD, or do you expect to then be able to play the DVD on
a DVD player attached to a TV? You can use a DVD to store computer readable
data and used on another computer, but it cannot be used to view a presentation
on a TV. To do that, use the DVD/CD burning software that came with your DVD
burner.
If you need to view the presentation on a TV it's a very different task and you
should read through the following:
Convert presentations to VHS or DVD video
http://www.rdpslides.com/pptfaq/FAQ00156.htm
Sonia Coleman
Microsoft PowerPoint MVP Team
Autorun Software, Templates and Tutorials
http://www.soniacoleman.com