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.

When Microsoft rolled out Office 2007, the company made some fundamental changes to its file formats, updating them from binary files to XML-based packages. The default format for Excel 2007 followed ...

If you have an old Excel spreadsheet, Excel opens it in normal view, which might be risky at times when it is downloaded from an unknown source. As many people Unblock the downloaded file without ...