HELP....Dual Monitor Issue!

How to I get my excel to allow me to use dual monitors without opening new instances? A few years ago, I was not able to do this, then an upgrade must have occurred and we were able to very easily use both monitors by simply moving one screen to the next, without having more than one instance of excel running. Now I changed jobs, and I cannot use the dual monitors again unless I open two instance, but then I cannot paste as easily and it is a pain. We are using Microsoft Home and Business 2010 Version 14.0.7177.5000 32 Bit.
Any ideas how I can get this amazing function back??
Thanks so much for your help.

If I "un-maximise" an excel window, I can drag it to my other screen, still using the same instance of excel

That's a capability introduced in Excel 2013; see https://msdn.microsoft.com/en-us/lib.../dn251093.aspx

All earlier versions of Excel have a multiple-document interface.

You're welcome.

Hi,

You can stretch the Excel application window across both monitors and then tile the workbook windows within it, one per monitor. I have done this often at work where we still use 2010.