Applying bold to selected word in a Word document

[Keef]

When I select a word and change it to bold, the whole document changes to
bold. If I then hit Ctrl Z the rest of the document changes back to normal
but leaving the selected word as bold.

 

[garfield-n-odie]

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