When you open a workbook of 97-2003, Excel 2013 enters the compatibility mode-indicated on the title bar-where it decontaminates the new configurations which cannot be indeed shown or converted by preliminary versions. When you save a workbook, Excel 2013 saves Excel 97-2003 files in their older format using compatibility mode. The workbook stays in compatibility mode until you convert it to the Excel 2007-2013 file format. Excel 2007, Excel 2010, and Excel 2013 use the same file format, so you don’t need to convert files between them.
Convert an Excel 97-2003 to Excel 2013
1. Open the Excel 97-2003 workbook you want to convert to the Excel 2007-2013 file format.
The Excel 97-2003 workbook opens in compatibility mode.
2. Click the File tab, and then click Info.
3. Click Convert.
4. Click OK to convert the file to the Excel 2007-2013 format.
Excel exits compatibility mode, which is only turned on when a previous version is in use.
Did You Know?
You can display extensions in the Save and Open dialog boxes and Recent Documents list. Changing the Windows option also changes Excel. In the Folder Options dialog box on the View tab, clear the Hide Extensions For Known File Types check box.