Preventing the fonts from changing

[Molodets]

I am editing a report whose initial draft was cobbled together by a number of
people using different fonts, including material copied from the Internet. I
can change the various fonts to our institutional standard, Courrier New 12
pitch, and sometimes change the whole document by selecting all and
indicating Courrier new, 12 pitch, but the changes won't stay changed!
Various bits and pieces keep changing back to their original fonts and sizes
when the document is reopened or when text is moved around. Is there some
global setting I can use that will force the entire document to the font I
want and keep it there?

Thanks in advance for any help.

 

[grammatim]

Probably there are many different paragraph styles using different
fonts.

You could apply a single style to every paragraph.