Files created in Microsoft Word 2010, Microsoft Excel 2010, and Microsoft PowerPoint 2010 can be opened in the 2007 Office release programs without special add-ins or loss of functionality The newest version of Microsoft Office automatically saves in a new Microsoft XML format and users who have Office 97-2003 may not be able to open documents unless you save as an earlier version.
Check compatibility between your Microsoft Office 2010 files and earlier versions to check for features that are not supported.
Click File > Info > Check for Issues > Check Compatibility
Click Select Versions to show and make your choices. New features that are not compatible will show up.
Save as an earlier version of Office so that people using older versions of Office (97-2003) can open the file.
Click File > Save As.
When the Save As window opens, click the down arrow beside Save as type: and, depending which Office program you are using, select