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.

Convert OpenOffice.org Calc spreadsheets into a Microsoft Excel file to take advantage of Excel's built-in tools. OpenOffice.org spreadsheets default to a .xsc file extension, which certain versions ...

If you notice that your Excel files are opening in Notepad, then read this post to learn how to fix the issue. The default behavior of a document or file is to open in the application with which it ...

BearPup sometimes wants to open a file in one program, and other times open it in another. He asked the Answer Line forum for an easy way to do this. Windows uses a file’s extension–the part of the ...

Microsoft is making it easier to change your default file associations by adding a new search feature that lets you quickly find the extension you wish to modify. When a program is installed in ...