I use Evom from The Little App Factory to achieve this. It works very well and it's free.
Once you download it, you will see this window:
Drag and drop the video(s) onto the window and another window will pop up.
For the most amount of control, I recommend the "Folder" tab. Here, you can create a new name for the file, select where you would like it to go, a range of formats, and even the quality. After that, select "Convert".
In my case, I selected it to be converted to an MP3 file and move it to the desktop. Here's the result.
This process is very easy and you can even convert more than one video at a time.