I’ve always found Word’s AutoCorrect and AutoFormat-As-You-Type to be Word’s most annoying features. If you have them engaged, Word will try to guess what type of formatting you want based on how you write the paragraph, how you manually format the paragraph, or by how you formatted something before it. If you upload a Word file to Smashwords with paragraphs formatted inconsistently, like some paragraphs formatted as “Body Text” and others formatted as “Normal Text,” the book will look horrible as an ebook. To turn off the features, in Word 2000 & 2003, go to “Tools”: “AutoCorrect,” then click on the “AutoFormat As You Type” tab and then uncheck most of the boxes, and then click on the “AutoFormat” tab and uncheck the four boxes under “Apply.”
The reason we want to turn off these AutoFormatting options is because later in the Style Guide, you’re going to try to simplify and normalize your text to prepare it for conversion. If you don’t turn off AutoFormatting, Word will cheerfully and automatically mess things up again as you make the corrections below.
To access the same screen in Word 2007, Word 2010 or later, click on the round Microsoft Office button (upper left) then click Word Options, then click Proofing, then click the button at right for AutoCorrect Options. See the screen shot below, which is similar for most versions of Word.