The latest Office software of Microsoft Office System 2007

Microsoft Office 2007 Compatibility Pack

Microsoft Office XP and 2003 systems Word, Excel or PowerPoint program's user should first install all high-priority update from the Microsoft Update, and then download the Compatibility Pack.
When you install this compatibility pack on the computer which has installed Microsoft Office 2000, Office XP or Office 2003, you can open, edit and save more advanced file.The Compatibility Pack can also work with Microsoft Office Word Viewer 2003, Excel Viewer 2003 and PowerPoint Viewer 2003, in order to view files saved in these new formats.
The latest Office software of Microsoft Office System 2007 is not only has a revolutionary change in the program interface and the save format default by office document has also changed. The common Office document file format extensions have increased an X compared with the earlier versions of Office (Office 97,2000, XP, 2003), such as Word documents. DOC format has changed into. DOCX format, Excel spreadsheet. XLS format has changed into. XLSX format, and so on.
Because earlier versions of Office do not support this new format for Office 2007, so if you open these document formats would be more trouble if you  without installing Office 2007 on your computer.