The Microsoft Office 2007 suite utilizes a new file format known as Open XML. This new format introduces an “x” at the end of the file extension (see Figure 1) and will affect compatibility between the versions for the following programs: Word, Excel and PowerPoint.

Working in Office 2007
Documents created in previous versions of Office are able to be opened in Office 2007 without any problems. This is called backward compatibility. When you open a document created in a previous version of Office, you will see “Compatibility Mode” in the title bar of the document window indicating that Compatibility Mode is turned on.
Note: With Compatibility Mode turned on, none of the new or enhanced features of Office Word 2007 will be available. This is so that users of previous versions of Word will have full editing capabilities.
You have two choices:
1. Work in Compatibility Mode and not utilize any Office 2007 new features.
2. Convert your document to the Office Word 2007 file format and have access to the new and enhanced features in Office Word 2007.

It is important to note that users on previous versions of Word may be prevented from editing certain portions of the document that were created with some of the new features in Office Word 2007.

Download pdf Microsoft Office 2007 Compatibility Pack End User