Opening Office 2007 files in older Office versions
If you use Microsoft Office editions 2000 through 2003 and aren't ready to
upgrade, you should be able to open work that someone else saved in the
new, 2007 formats. However, this process isn't seamless. First, you must take steps to allow the older software to read the newer file.
The Compatibility Pack download that makes this possible requires that you run
Word, Excel, and PowerPoint 2000 or 2002 with Service Pack 3 or run the 2003
editions of those applications with SP1 or higher. Your operating system must
be Windows 2000 SP4, Windows Server 2003, or Windows XP with SP1 or newer.
Microsoft Office 2003 and 2000 should prompt you to download the Compatibility
Pack when you try to open Office 2007's Open XML-based files.
If you're running older Office software that meets these
requirements, you should receive a one-time prompt to download the
Compatibility Pack when you try to open a 2007 Office file. However, without
the latest software updates, the Compatibility Pack may not fully work.
If you try to open an Office 2007 file with Office 2003 or 2000 but aren't prompted to install a Compatibility Pack, then you probably need to update your older Office software first, by visiting update.microsoft.com. When that's done, you can restart your machine and get the Compatibility Pack at download.microsoft.com.
After you've installed the Compatibility Pack, you must restart your computer for the changes to take effect. With that done, you should be able to open Office 2007 files with older Office software. If you open an Office 2007 file in Office 2003, choosing Save will keep that file in the new format. The same is true for Word 2000. In Excel and PowerPoint 2000, however, you must choose Save As to keep an Office 2007 file from reverting to an earlier format.