Do you know what the number one download is at the Microsoft Download Center – no cheating and looking at the subject line :-)
Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint File Formats
Open, edit, and save documents, workbooks, and presentations in the Open XML file formats which were introduced to Microsoft Office Word, Excel, and PowerPoint beginning with Office 2007
Some caveats before you use this pack though:
- Users of the Microsoft Office XP and 2003 programs Word, Excel, or PowerPoint—please install all High-Priority updates from Microsoft Update before downloading the Compatibility Pack.
- If you use Microsoft Word 2000 or Microsoft Word 2002 to read or write documents containing complex scripts, please see 925451 for information to enable newer versions of Word documents to be displayed correctly in your version of Word.
- The Microsoft Office Compatibility Pack has been updated to include SP2. Additionally, with the updated Compatibility Pack, if .DOCX or .DOCM files contain custom XML tags, those tags are removed when the file is opened in Word 2003. For more information, please see KB978951
- Supported Operating Systems: Windows 2000 Service Pack 4; Windows Server 2003; Windows Vista; Windows Vista Service Pack 1; Windows XP Service Pack 1; Windows XP Service Pack 2; Windows XP Service Pack 3
- Recommended Microsoft Office programs:
- Microsoft Word 2000 with Service Pack 3, Microsoft Excel 2000 with Service Pack 3, and Microsoft PowerPoint 2000 with Service Pack 3
- Microsoft Word 2002 with Service Pack 3, Microsoft Excel 2002 with Service Pack 3, and Microsoft PowerPoint 2002 with Service Pack 3
- Microsoft Office Word 2003 with at least Service Pack 1, Microsoft Office Excel 2003 with at least Service Pack 1, and Microsoft Office PowerPoint 2003 with at least Service Pack 1
- Microsoft Office Word Viewer 2003
- Microsoft Office Excel Viewer 2003
- Microsoft Office PowerPoint Viewer 2003