This happens because of the codecs or the lack of codecs. I strongly recommend installing CCCP Codecs and then try again, because CCCP Codecs use FFDShow which is highly compatible with all the converters.
Download from this page: http://combined-community-codec-pack.software.informer.com
Secondly, while converting, use other video and audio format. For example, convert it to MP4 and use AAC as audio or MP3 codecs.