Identify Fields That Change When You Open and Print a Document
The Problem:
All I did was open the document and print it. Why is Word asking me if I want to save changes when I close the document?
The Solution:
The document contains one or more fields that were updated automatically either when the document was opened or when it was printed. Often, the field that changes is a date field that changes to the current date, so check that the printout contains the date you want it to have. For an older document of which you're printing a new copy, you probably will neither want the date to change nor want to save the changed version of the document. To prevent Word from updating the field when you print, choose Tools 
Options, click the Print tab, and uncheck the "Update links" box.
If you can't immediately identify the field, choose Tools Options, click the View tab, choose "Always" in the "Field shading" drop-down list, click the OK button, and then look for the shading in the document.