Can anyone tell me why the Equation Editor is disabled in Word 2007? Is it an
add-in that I ned to get from somewhere?
There are two separate equation editors in Word 2007.
The old one can be invoked through Insert > Object > Microsoft Equation 3.0. To
make it available in the list of objects, you may have to rerun the Office setup
program, choose to add features, and select the equation editor from the "Office
Tools" group.
The new editor, invoked through Insert > Equation or Alt+=, doesn't need any
special setup or add-in. If it doesn't work, try going to Office button > Word
Options > Resources and clicking the Diagnose button.