How can I determine which version of Excel was used to create a .xls file?

Does anyone know of a way to determine which version of Excel was used to create a file? We have some .xls files and need to determine the version. They open fine in Excel 2007 and higher, but a co-worker wants to determine their exact original version.

I've examined hex dumps to do similar forensics on .doc and image files, but I can't find anything particularly useful in the .xls file and the extended properties don't seem to help either.

Solution 1:

Microsoft KB 178605: How To Determine the Version of a Microsoft Excel Workbook (snapshot)

Microsoft Excel saves data using structured storage. In particular, it creates a data stream called "Workbook" (previously just "Book") where it saves the contents starting with a BOF (beginning of file) record. This record contains useful attributes of the workbook, as well as the version.

That article goes on to give sample C++ code to dump this information.

Also see, Stackoverflow,
How to identify whether an Excel file conforms to Excel 95 or Excel 97 specifications?

Solution 2:

You could also save the excel file with the .zip extension. Then open that archive and look in the docProps folder. Open the app.xml and check the AppVersion node:

16.0300

Solution 3:

As far as I know, in the Meta Data it simply stores it as "Microsoft Excel".

Other than looking at the file for the version e.g. .xlsx for 2007 and 2010, or .xls for 97-2003 (could be older, but unlikely), I am not sure there is a good way to find out.

Why does your co-worker want to know? If you say what the goal is other than finding the version number, I may be able to help you find another way of achieving it.