I downloaded Wolfram's Intro to Mathematica in Notebook format. I like to experiment as I study but you can't edit the notebooks. They are locked for some reason. So I still have to open a work notebook, taking up more room on my small screen, and my vision isn't that great.
Is there some way to unlock the notebook so I can edit it? It's a standard .nb so I figured there must be an option I can't find.
I tried Notebook Properties in Options, but it says Editable True, which is not true. And it's grayed out so you can't change it anyway.