Does it print?

PDF to Word conversion is not perfect.

What program was used to create the letterhead?
Does that program allow saving as a Word document?

You may be better off saving the letterhead as a graphic and importing that into Word.

Your letterhead should be saved as a template and the letterhead, itself, should be the first-page header for your template.

• How can I get a different header/footer on the second page?
• Setting Up Letter Templates - Ribbon by Suzanne Barnhill, MVP