How do I stop Word 2007 from automatically converting a single quote to an apostrophe?

Here are the steps to disable Word from formatting the ' to a ’.

• Click the Office Button in the top left corner, open Word Options
• Go to Proofing then to AutoCorrect Options...
• Click on the AutoFormat tab
• Under Replace uncheck the box labeled : "Straight Quotes" with "Smart Quotes"
• Click on the AutoFormat As You Type tab and uncheck a similar box to previous one.

I tested and Word does not replace my single quote with an apostrophe for contractions.

I've just struggled with the same problem but found the definitive solution: What the guides don't say is that the "smart quotes" option appears in two different places: one tab called "AutoFormat" (which I think we were all going for) and another tab called "AutoFormat As You Type" (which I had not noticed). You have to disable it for both tabs if you really want it to stop.

Open the MS Word options by clicking on the Office icon in the upper left corner. Click on the smaller "Word Options" button in the lower right portion of that menu. This will open a new window. Click on the "Proofing" tab on the right, and finally click on the AutoCorrect Options button to reach the options window shown below:

You are referring to "Smart Quotes"

Here is an article that will explain how to turn them off: http://www.howtogeek.com/wiki/Disable_Smart_Quotes_in_Word_2007