How to fix Different format than specified by the file extension in Excel 2010

After upgrading to Excel 2007 or Excel 2010, an error specifying the file you are trying to open .xlsx is in a different format than specified by the file extension when you try to open an excel document: The file you are trying to open .xlsx is in a different format than specified by the …

Read moreHow to fix Different format than specified by the file extension in Excel 2010