Word, Excel, and Powerpoint save files in new XML-based formats in Office 2007. One advantage--any application that supports XML can access and work with the information stored in the new file formats, whether that application is part of MS Office or not. In addition, the new file formats are more robust (less susceptible to corruption), more efficient (smaller file sizes), and secure (you can easily remove personally identifiable or business-sensitive information like user names, comments and file paths).
The new files also have new extensions. Instead of .doc, Word files are saved as .docx. Instead of .ppt, Powerpoint files are saved as .pptx. Excel workbook files are saved as .xlsx rather than .xls.
These new file formats in Office 2007 are backwards-compatible with older Windows versions of Office (specifically Office 2000, XP, and 2003). If your machine has been kept up to date with Microsoft Update (which should include any machine in the IASTATE domain), you should already have the ability to open 2007 file formats in Office 2003. What this means is that if one person in your office upgrades, everyone else in your office can still open, read, and edit those files. Some features that are strictly available in Office 2007 won't be available; however, the basic information and layout will be intact.
When you try to open an Office 2007 document in Office 2003 for the first time, you will see a prompt that says, in effect--this is a new file format, do you want to download a plug-in to enable Office to read it? Once you've downloaded and installed the plug-in, you will be able to open Office 2007 XML files.
Finally, it is always possible to save files in Office 2007 as Word 97-2003 documents rather than save them in the newer format. You can either do this with individual documents or you can change the default so that you always save in Word 97-2003 file formats. The disadvantage of this solution is that you lose some of the new features of Office 2007 when saving to older file formats.Posted by dcoates at January 12, 2007 10:17 AM