Does your DVD work on Windows Media Player (WMP) with audio? If it doesn't then you should download the appropriate decoders to make your DVD work before you try to convert them using M²Convert for PSP. I'm asking this because our M²Convert applications use the same decoding technology that WMP uses to playback the DVDs.
What is your operating system?
Do you have any other DVD playing software installed? Which one(s)?
Please note that M²Convert is not compatible with Nero media. If you have this installed, M²Convert will not be able to convert DVDs even if they play in WMP.