Microsoft Word 2007 creates files in the .docx format by default. So, unless you save files in compatibility mode, you will not be able to open those files in previous versions of MS-Word. Microsoft Word 2003 will simply not recognize .docx files, and will throw up an error message. However, Microsoft has provided an answer for this dilemma, in the form of a “Compatibility Pack”.

The Compatibility Pack for MS-Word lets you open the .docx files without using MS-Office 2007. You can open not only .docx files, but also .xlsx (MS-Excel 2007) and .pptx (MS-PowerPoint 2007) files in older versions of Microsoft Office™, by installing the pack, which is available for download, completely free of cost, through MS-Office Online service.


The Compatibility Pack will not provide all the services provided by Microsoft Word 2007: in fact a number of services and options are restricted, or altered completely. These restrictions include the following:

Themes - The themes are irreversibly converted to styles when you open a Word 2007 file using the Compatibility Pack. This cannot be automatically corrected, even if you open the file later in MS-Word 2007 again.

Equations – This feature was introduced in MS-Word 2007, and was not present in previous versions. So, if equations are displayed in text format, these may not show up correctly.

Content controls, bibliography, citations, placeholder text – These elements vary greatly in structure in Word 2007 from previous versions. The Compatibility Pack automatically converts these into static text, in order to avoid visual anomalies.

Fonts – These are permanently and irreversibly changed to static formatting. If you open the file later in Word 2007, the fonts will not be automatically converted to another style.

In spite of these drawbacks, the Compatibility Pack is an invaluable tool that helps people who do not have MS-Word 2007 to access .docx files. If you do own a copy of MS-Office 2003 and have to work with .docx files on a regular basis, the Compatibility Pack may be your best bet.