You really need to start a new thread about this. You posted another in the Sansa Media Converter board which is the correct board for such a discussion, but gave no details regarding your situation.
You have given a few more here, but still not enough for anyone to adequately help you.
Have you read any of the existing threads on this subject, or tried searching for a similiar issue that might help? Have you tried viewing any of the ‘How-To’ videos SanDisk has created to help you, including one on ‘how to put videos onto your player’?
A lot depends on the source video; what format it is, where it came from (like DVD or download), etc. There are a lot of video formats out there and what works with one, won’t necessarily work with another. Most people who have successfully converted videos to use on their players have found that they need to first convert the video with another software program before just dumping it into SMC.
I’d suggest you go back to your post in the other board and continue in that thread and give some details about the video you are trying to convert, what version of SMC you’re using and any other specifics about what exactly you’ve done and the result, if any. Or start a new thread in this board.
I’m sure someone here can help.