The Word, Excel, and PowerPoint 2007 file formats and some of their features aren’t fully compatible with earlier versions of the programs. Although people running earlier versions will be able to open these Office 2007 files using a converter (provided they’ve installed it, of course), some features and/or content might be changed or lost. To see which features aren’t fully compatible and will be changed or lost, run the Compatibility Checker before you distribute the document, workbook, or presentation.
With your document, workbook, or presentation completed and saved, click the Office button.
On the Office menu, point to Prepare, and choose Run Compatibility Checker to display the Microsoft Office Compatibility Checker dialog box for that program.
Scroll through the list of items that will be changed or lost.
If you’re not sure whether the changes are acceptable, point to Save As on the Office menu, and click the program’s 97–2003 format in the gallery that appears. In the Save As dialog box, enter a different name for the file, and click Save. Scroll through your file and examine the changes to see whether they’re acceptable. If they are, distribute your original file; if they aren’t, edit the file to eliminate the incompatibilities.