A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
I found that it I needed to resave the PERSONAL.XLSB file.
Open Excel and then do VIEW/UNHIDE and unhide the PERSONAL.XLSB file. Make a change to the file and then do VIEW/HIDE and hide the personal file. Exit Excel and tell it to save the PERSONAL file when it asks. The next time you open excel it should have one instance.
Worked for me anyway.