This is a re-post of some words I wrote to someone in an e-mail. They had previously sent a file with a .docx extension, and I figure this post might be useful for others to reference as well!

Extensions
The file extension is the bit on the end of the file, after the period, that tells the user what type of file it is. Besides telling the user what kind of file it is, it also tells the computer what format the data is encoded in. That is: which way to interpret the bits of data that make up the entire file. Have you ever tried to open a file with the wrong program? If you’ve ever accidentally tried to open a file that has a “.jpg” extension with Microsoft Word, you know that what comes out is a bunch of odd symbols that aren’t being understood by human or machine.

This is similar to what we saw when we tried to open the file you sent! Many symbols that made no sense. We did use Microsoft Word, because that is how the file was created, but it didn’t work. Here’s why.

Even though the file you sent was created in MS Word, take a closer look at the extension. Your file ended with a “.docx”


Microsoft Word
I must confess that the “why” of this entire story is way beyond me, but the fact is that Microsoft introduced a new file extension along with the new version of Word. The new extension (which is also present in 2007 versions of PowerPoint (.pptx) and possibly also Excel) is not readable by older versions of MS Word. It’s encoded in a language that only Word 2007 understands. When you save a document in Word 2007 the default extension is “.docx” and unless you change that when you save, your document will only be readable by folks who have Word 2007.

How to make Shareable files
So, you want to fix your files:

1. With your document open go to File > Save As. (note: if you’re saving for the first time since your document was created, File > Save will do the same thing)
2. The Save As dialog box opens. Notice that besides naming your file here, you also have another option directly below the box where you type the name. This is the pulldown menu for Save as Type
3. Pull down the “type” menu. Notice that .docx is probably selected by default. Select “Word 97-2003 (.doc)” from the list.
4. Name your document, then click “Save”
5. A dialog box appears saying something like “Older versions of Office may not support the features of this document. Are you sure you want to save to an older format?” Click yes and don’t worry!
6. Voila! Your document can now be opened by any version of Word, not just the elite Word 2007.

How we fixed the problem
Please note that this process would be very difficult from any machine that has restrictions on downloading and running executable files! If you’d like to equip a Windows computer that’s running an older version of Word to open .docx files, here’s what you do:

Download and install the Office Document Compatibility Pack from the Microsoft Website

If you have a mac, the compatibility pack is here

Hope this helps in sharing future files!