How do I edit a rendered animation? I created a short animation and after rendering it, I must have had one/some of the nodes not set correctly.  I want to go back into the file and see what I did wrong, but when I open the file up it defaults to the rendered window.

I have gone through all the window settings and cannot find where/how to re-open the nodes panel to make adjustments and then re-render it.  Sorry if this was answered already.  I searched the forum in various ways and could not find this exact issue.  I consider myself a novice-intermediate level Blender user.
if you're seeing something like this(not including the cube):

then you need to go here:

and change it to node editor (or whatever you need to change it to. there are also other ones like that around.)