Microsoft will introduce new file types for its Office software

Microsoft has rebuilt its host of Office applications from the ground up.
Along with the bold interface changes and new features, revamped file
formats will affect how you work in Word, Excel, and PowerPoint, regardless of whether you plan to upgrade to Office 2007 from an earlier
version.



Microsoft Office 2010 software comes in a variety of flavors for home
users, small businesses, and enterprise customers.
That's because you'll need to take extra steps to share Microsoft's word
processing, spreadsheet, and presentation files with people still running
older Office applications. When you hit Save within Word, Excel, and
PowerPoint 2007, your work will be saved in the new file format by
default.



If you're using the 2000 through 2003 versions of Office, you'll be able
to open the new Office files after you follow Microsoft's prompts to
install compatibility updates. You'll also be able to open older Office
files within the new Office 2007 applications, although some of the new
features won't work until you save the older file in the most recent
format.



The 2007 file formats for Microsoft Office software are Open XML-based, so
they compress more information into fewer kilobytes and thus require less
hard drive space than their predecessors. An added X marks the extensions
of these new files; for instance, the DOC extension from Microsoft Word
will be DOCX in Word 2007, Excel's XLS becomes XLSX, and so on. Other
Office 2007 file extensions include DOCM, for Word documents that enable
macros. The Open XML format, also known as OOXML, will be open source.
However, Office 2007 software will not let you save work in either the
Open Document Format used by OpenOffice or in the formats from Corel
WordPerfect.



If you plan to share Office 2010 Download  files with people who use older
versions of Microsoft Office or rival Office software, here's what you
should know