http://word.mvps.org/FAQs/Formatting...tedContent.htm

should help you.

"Leverman1" wrote in message
...
In MS Word, I'm editing an old document I've saved to use as a new
document.
I select/highlight a single line and click on Bold and it Bolds the entire
document.
Same thing happens when I click on underline.
What can I do to stop this from occurring?