I used ClosedXML.dll to create Excel file, however ClosedXML saves the excel file as .xlsx and my client’s PC only runs Office 2003 so they cannot open the .xlsx file, how can I convert that .xlsx to .xls?
Any recommendations will be appreciated. Thanks to you all.
Ask your client to install the Microsoft Office Compatibility Pack, if possible, which will let them open Office 2007 format documents in Office 2003.