If you cannot open an Excel file and see Excel cannot open the file because the file format or extension is not valid error, see this post.

If you are unable to open an Excel file? You can use this tool to repair your corrupt Microsoft Excel files easily the right way.

For those cautious about third-party software, LibreOffice is a free and open-source alternative that supports various file types. If the file opens in LibreOffice, save a duplicate, which will then ...

How to Open an XLS File in Excel. 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 ...

Reader Paul writes in with an interesting tip for using relative paths in a batch file: you can use a special code to represent the current path—useful for batch files on a Flash drive.