im not very smart when it comes to this program but i tried uploading my video to youtube and it wouldnt let me. it said to make it into a widows movie maker file but when i tried to import it to windows movie maker it wouldnt work!
Youtube has a great help section on uploading see here to get started - this page would suggest that your video you are trying to upload is an unsupported format.
Read through the help pages and export your video from MEP to a supported fromat before uploading and use the Youtube upload page to put the video on Youtube.
Another thought for you, try exporting your video in MEP by clicking "Export" (top right hand corner of the screen), then click "Output as video file", under format, click the down arrow and then click on "MPEG-4" then click "Save File". Choose a location where you want to save the file, give the file a name, and click "Save video". Give MEP a few minutes to save the video and when you get the message that says "Export successful" click OK.
Now log in to your YouTube account, and click "upload" which is just to the left of your YouTube user name near the top right corner of your screen. Click "select files from your computer". Click on the file that you just exported, then click "open" and your file should begin to upload to YouTube.
Good luck, and let us know how you make out getting your file uploaded.