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 ...

This month's monster security patch for Office breaks Excel when it tries to open HTML files, and it seems unlikely Microsoft will fix the problem Excel users are reporting an odd bug in the way ...

Numbers has the ability to open Excel files so you can work on them. You can also export spreadsheets in Numbers so that they are compatible with Excel.

CSV files are special text files that are quite common when dealing with spreadsheets. Here's how to open and make them.

Microsoft Word can accommodate a surprising number of file formats, and even take in Excel and PowerPoint data, though it might look funny. Here's how.