A family of Microsoft word processing software products for creating web, email, and print documents.
Testing in a new user account is a good test. Since you don't have the problem in a new user account, it is likely that your Normal template has become corrupt. Normal is the name of the template Word uses to make a new, blank document and store macros and other settings.
Do the following in your regular account (the one having the problem)
Quit Word. (Make sure Word is actually not running. Closing all Word's open windows does not quit Word).
Navigate to the Templates folder, which Apple has conveniently hidden in your User directory.
http://www.wikihow.com/Unhide-the-User-Library-Folder-on-a-Mac
Rename Normal.dotm
When you open Word, a new Normal template will generate that should have default settings.
If this doesn't fix the problem, then delete Word's preferences.