I am having trouble transferring downloaded movies from Limewire and putting them on to iTunes.

I have everything right, the file type is mp4. But once I click and drag the file onto iTunes, nothing happens. I have been able to get some videos to transfer, but for some no matter what I do, they won't transfer.

I have tried going to file>add file to library and clicking on the correct file, and clicking ok but again, nothing.

I do not want a converter, I do not want to pay the money for the dvds and the converting them.

Any help is great.