There are many applications that allow you to convert your videos to other different formats, but the truth is that it is so easy to use and free, It makes the task a thing for children.
This Windows application allows for multiple video file conversions, ya sea wmv, avi, mpeg, mkv, android, mp3…to another format very easily.
First select the file and then convert the menu, there will choose which want. I always select AVI, because it is the most accepted on all systems. If you want to have your own, choose the option “Add your profile” which will create a custom.
The source size is very important, because if we convert one source is 320×240, not make much sense to convert 640 x 480 for surely it will be worse (That's what the option “frame size-Original”), although, you can try to see how it looks.
In the audio section, the logical thing would turn to something close to the original format, for example, If the original is in aac-32000Hz-96kbps-Mono, The normal thing would transform to mp3-32000-96kbps-Mono, but good, everything is to try to get it right.
What do you use you?