Ok, I needed to convert from .mp4 to .avi, so this is what I did. I downloaded Boilsoft. There are many kinds of boilsoft video convertors so get the right one. After I downloaded I found out it was a free trial.
Than I went to this site to get it to run without buying it:
Just find boilsoft trial version and go to that site, than you can convert your video.
By the way, WELCOME TO THE FORUM!!