This scenario happened today at work: a colleague was looking for quotes on a meeting hall and food catering service for an upcoming professional association meeting. One contact responded by email with two attachments: one a .doc file and one a .docx file (each file contained different information). She was able to open the .doc file no problem (it is a Microsoft Word file), but could not open the second (also a Word file).
This is because Word 2007 saves its documents in the .docx format by default. Unfortunately, Word 2003 (or older) cannot open .docx files. Those who use Word 2007 often forget this, or may not realize it, especially if they have the display of file extensions turned off, which, again is a default in Windows XP and Vista.
The Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats, which you can download if you already have Office 2003 installed: Click here to go to the download page.
Note these details:
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.
By installing the Compatibility Pack in addition to Microsoft Office 2000, Office XP, or Office 2003, you will be able to open, edit, and save files using the file formats new to Word, Excel, and PowerPoint 2007. The Compatibility Pack can also be used in conjunction with the Microsoft Office Word Viewer 2003, Excel Viewer 2003, and PowerPoint Viewer 2003 to view files saved in these new formats. For more information about the Compatibility Pack, see Knowledge Base article 924074.
Note: If you use Microsoft Word 2000 or Microsoft Word 2002 to read or write documents containing complex scripts, please see http://support.microsoft.com/kb/925451 for information to enable Word 2007 documents to be displayed correctly in your version of Word.