If you have Encore 2.0, that's almost 4 years old - but the vintage of the software is not important.
Instead, look in the FAQ on this forum for software to avoid/remove - many codecs and other DVD burning apps can "break" Encore's burning functionality.
If you need a quick fix, try building a DVD image from Encore, and then burn it from Nero.
Well that brings me to another question. I have burned my project to a file on my computer using Encore. Then I use nero to burn to a DVD, but what I get is a file folder with the DVD movie file within it. Of course when I double click on that file it will play. So my question is , "How do you burn the files so that when you put it in a DVD player it starts automatically?"
You built a DVD image from Encore? Are you using Nero to burn it? If so, there's a specific command in Nero that I can't remember right now - search Nero's help for "image".