XLS files are Excel workbook files created in Excel 97 or Excel 2003. The 2007, 2010 and 2013 versions of the program use the XLSX format by default to save workbooks, but can also use the XLS format.

All,<BR><BR>We are still on Office 2000 with Outlook 2003. I installed the office 2007 compatability pack on a few computers to convert from the DOCX and XLSX to 2000 format to read, and this works on ...

Microsoft went to the Open XML Format for its Office documents beginning in 2007. The Open XML format files are smaller than previous file formats. An Excel Workbook 2007 or 2010 business file ...