How to Determine an MS Excel File Version

1. Click on the Windows “Start” button then on “Computer” to open Windows Explorer.
2. Browse your computer to find the Excel file.
3. Check the file extension. If it is '.xlsx' then the file was created with Excel 2007. The extension '.xls' indicates older program versions.
4. Right-click on the Excel file and choose “Properties” from the pop-up menu.
5. Select the tab “Details” (in Windows Vista or 7) or “Summary” then “Advanced” (in Windows XP).
6. Read the Excel version in the line “Type,” for example, 'Microsoft Office Excel 2003.'