How to restore original window? So today I wanted to separate the workspace between two monitors and I shift-clicked the view I wanted to put in a new window and it worked.

The problem is that when I wanted to close it (since in any editing program I know closing the main window closes all the others and then at the startup restores them) I accidentally closed the main one and the secondary window stayed open (I was surprised a lot :D) and I don't know how to restore the main one with the top bar (you know, the one which has File, Edit...) and the original layout because in the secondary window there is only the view.

So how do I restore it?
Do not open the file double-clicking it, instead open blender and go into File > Open.

Then deselect the checkbox "Load UI".

Open the project and you are done!