Microsoft office compatibility Pack is one of the Must install if you are running Microsoft Office Pririor to MS Office 2007.

The Office 2007 application such as Word, Excle, PowerPoint, will no more than use the Older File Extention like .doc for Word, in fact the new Word 2007 uses .docx as its Default format…

So even if you dont have any thing to do with MS Office 2007 but your clients of contacts may use the new office now when they save a file ex. in Word 2007, they will find file saved as Default format .docx, so when you receive such file this free update will allow your older Office setup, like Office 2000, Office XP and 2003 to access those files and open them for you…

Download the Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats.

This is a Very good Tips for MSOffice 2007 users, Taken from chotocheeta.com

When you save a document under Microsoft Office by default MS Office 2007 applications uses a new file format to save the file, for example

Microsoft Word 2007 will use new file format .docx
Microsoft Excel 2007 will use new file format .xlsx
Microsoft PowerPoint 2007 will use new File format .pptx

Now when under any of these application you click Save As they will offer option to save as Older MS Office Compatible file formats,

or you can force word to save in that format by default instead of new format, By Visiting Word Options,

Then go to Save TAB (Located at the Left Navigation Panel, and under that  Change the option Save file in this format to Word 97-2003 Document (.doc)

Thats it, it will force Word 2007 to save as .doc in default Save command !!!

Process is same under PowerPoint and Office Excel 2007…

Question may come why would you need it, the main reason is the Older Version of  MS Office by default is not compatible with the new format, so if you send any file saved under new format will not going get open in older MS Office system. Without the Help of Microsoft Office Compatibility Pack but thats not under your control to make sure that recipient of your Document has installed that under his or her system…