We seem to be stuck in some kind of a circular logic paradox. You asked "How do I set it up so I can have 2 separate windows open at the same time, one with each workbook in it?"
And then you say "opening 2 windows within that space results in insufficient area to see what you are doing"?
I have been assuming that you are already adjusting the zoom of each window within it's alloted screen real estate.
Unless that option has been overlooked or unless you are able to clarify something that I'm not understanding propertly, I fear we are at an impasse.
OK. Maybe I'm assuming that you know what I'm trying to do and you don't. So I'll try to be as specific as possible.
If you have 2 Excel workbooks open on your Windows toolbar at the botttom of the screen, when you click on Excel workbook A, Excel workbook A opens on your monitor. When you click on Excel workbook B, Excel workbook B opens on your monitor and Excel workbook A is minimized so you can't see it on the screen at all. And you can toggle back and forth between Excel workbook A and Excel workbook B.
I want to cascade Excel workbook A & B so they each take up half of the screen and are totally separate. Then I can drag and link items from A to B without having to minimze one and maximize the other constantly. The same way that you would by opening Windows Explorer in 2 separate windows to copy and paste files without having to navigate to the new location each time. When I try to do that with Excel, Excel will only open in one window and will toggle back and forth between workbooks, not allowing both to be opened at the same time.
I can't open Excel twice (I don't even know if that's possible to do) because the financial software that I am using incorporates Excel within it's program and Excel must be opened through that program. And that program cannot be opened twice.