A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
This may be caused due to an add-in template located in the startup folder of Office and Excel.
Clear the files from Office startup folders and Excel startup folders from the locations mentioned below and see if it helps:
C:\Program Files\Microsoft Office\Office14\Startup
C:\Users<User Name>\AppData\Roaming\Microsoft\Word\Startup
C:\Program Files\Microsoft Office\Office14\Xlstart
C:\Users<User Name>\AppData\Roaming\Microsoft\Excel\Xlstart