A family of Microsoft word processing software products for creating web, email, and print documents.
You can do it any number of ways.
The simplest is:
- open File Explorer, shortcut <WIN><E>
- navigate to the folder where the file is located
- single click on it
- press <F2>
- type the new name
- press <enter>
You can do a variation of that process directly in Word as long as the file is NOT open. Open the File Open dialog (which is a specialized version of the File Explorer), single click, <f2>,change name, press enter.