How do I ensure that the font attributes do not affect all of tex.

[Mtess45]

When I select text and I ex. Bold the line, the text within entire document
is bolded. This will happen with any type of font attribute that I try to
apply. I am then required to undo the entire doc then the changes remain...
Is there a setting that has to be deactivated to resolve this?

 

[Jay Freedman]

When I select text and I ex. Bold the line, the text within entire
document is bolded. This will happen with any type of font attribute
that I try to apply. I am then required to undo the entire doc then
the changes remain... Is there a setting that has to be deactivated
to resolve this?

See http://word.mvps.org/FAQs/Formatting/WholeDocumentReformatted.htm.