New file formats/extensions

Office 2007 saves files in a new XML format that is supposed to increase reliability and save space. Each document is actually several files saved together, compressed with the zip format. They appear as one file.

Office 2007 also puts new file extensions on its documents that are not recognized by other programs—even by earlier versions of Office.

Previous Office Versions

Word: .doc

Excel: .xls

PowerPoint: . ppt

Access: .mdb

Office 2007

Word: .docx

Excel: .xlsx

PowerPoint: .pptx

Access: .accdb


Compatibility: Office 2007 and other Office Versions

On CCSF Faculty and Staff computers the official, installed version of Office is 2002 or XP, which includes Word, Excel, PowerPoint, Access and Publisher. Now, Office 2007 is making an appearance on some computers:

  1. In student labs, in locations where Office 2007 is being taught and in the Faculty/Staff lab in Batmale 313 on the Ocean campus..
  2. On new Faculty/Staff computers, especially laptops.
  3. On some entire campuses (e.g. CHN)

Compatibility Problems compatibility icon

Documents created in Office 2007 don't open in older versions of Office.

So: If your students send you 2007 documents and you don't have Office 2007, you can't open them, and vice-versa.


For those trying to open Office 2007 Documents in earlier Office versions: Download the free Compatibility Pack from Microsoft:

To Share Office 2007 Documents

- with folks who have earlier Office versions

Use the Office Button to Save As a format other than Office 2007 in Word, Excel, or PowerPoint:

  1. Save As 97-2003 Document in Word, Excel, or PowerPoint: Saves as the old file format, with the old extension —compatible with older Word versions. When working with the document after you save, you'll see Compatability Mode in the title bar to remind you that not all 2007 features will be fully supported.
  2. Word only: Save As .rtf: The Rich Text format is supported by all word processors and preserves most formatting from 2007.

To Save as RTF:

Click the Office Button

Then click Other Formats.

Then choose Rich Text Format from the Save as type box

The PDF Option

Of course, you can always convert your Office 2007 file to a PDF that can be opened by the free Acrobat viewer—a good choice for the Web, since 95% of computers have the free reader for pdf files. Microsoft provides an Add-in for Office 2007 that allows you to save directly to PDF. It's free and available at

Problems downloading

Since Office 2007 files are actually zipped collections of files, some browsers download them with the wrong extension.

So double-clicking on these files doesn't open them in the right program.

If you are teaching Office 2007 and must send out and post files in the new formats, this is a problem.


Some browsers—specifically some versions of Internet Explorer (Windows and Mac), and Safari (Mac)—change the extension of the files to .zip when they download.

Before these files can be opened in Office 2007 by double-clicking the extension has to be changed manually to the correct extension for the application:

Word: .docx

Excel: .xlsx

PowerPoint: .pptx

Access: .accdb

A Simple Solution

Tell your students to use the Firefox browser, available for both Windows and Mac. It treats the new formats right: they download with the proper extensions. Double-click the file to open as usual.