A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
In order for this to work you need 2 instances of Excel open.
So open your first workbook and then while holding the ALT key down right click on the taskbar icon and open another workbook. Continue to hold down the ALT key until you get a popup asking if you want another instance of Excel. Click yes and then open your second workbook. If you do not get the popup make sure your holding down the ALT key long enough.