Office 2007 File Compatibility
With the release of Office 2007, Microsoft has introduced new Word, Excel, and PowerPoint file formats. These have an ‘X’ added to their file extensions (examples: .docx, xlsx, pptx). People who use Office 2007 are able to save their files as Office 2003 files to achieve greater compatibility. Follow these easy steps to save a Office 2007 document so that people using Office 2003 (or older) can view, edit, and save it.
NOTE: The steps above illustrate saving a Word document. To save an Excel or PowerPoint document, follow the same steps. The only difference will be Step 2, you will select Excel 97-2003 Document or PowerPoint 97-2003 Document.