Howtogeek posted a guide about disabling he Mini Toolbar and Live Preview in Word 2010 or 2007

A couple of enhancements in Word 2010 & 2007 is the Mini Toolbar and Live Preview features. While these enhancements are welcome by some, other users may find them annoying. Here is how to turn both features off.

Mini Toolbar and Live Preview Features
The Mini Toolbar pops up when you select text in a document. It allows you to change fonts, underline, bold, italicize the selection and more.

  Disable the Mini Toolbar and Live Preview in Word 2010 or 2007