If you're trying to burn this as a movie that can be played on a stand alone DVD player, then you're probably out of luck without finding new software. Most free ones, and those bundled with drives, won't handle AC3 audio.
I am trying to burn dvd's from downloaded avi(most of which use the ac3 filter). When I try to burn them, it says unsupported audio format. How do I incorporate the ac3filter with the avi's so they will burn properly? I am using Nitro Burn and Go CD/DVD. I have winxp. I have a 120gb hard drive with a 2.6gh processor and 512 mb ram. I am using an internal Lite-On DVDRW LDW 411S. Can somebody explain how to fix this problem please? Thank you