I am needing to upload some videos onto youtube or vimeo, but I can't because the files are .prel. But PE is not letting me export the files into something else, like .MOV. I am using the free trial version. Is this why?
The PREL extension file is the Project file. You need to Export/Share to an AV file. This ARTICLE will give you background on the PREL files. For suggestions on Export/Share for YouTube, you will want to see this FAQ Entry.