If you are working with Word at home or in an office environment where the systems people have not locked Word to prevent you from fooling with settings, there are three approaches you can use to choose a font and set it as the default.
All have worked for me in various Word versions. If one does not work for you, try one of the others.
The first step you have to take, no matter which approach you try, is to go to Word's Tool menu and choose Options.
In the Options dialog box, click on the Save tab.
Find the line reading: "Prompt to save Normal template" in the Save dialog box.
Click on the line to put a check in the box. Click on OK.
For your first attempt to make your font choice permanent, click on the File menu, then on New.
In the dialog box that opens, click on the General tab, then on Blank Document, then on OK.
When the document opens, click on the Format menu, then on Font.
Choose your font and the size you want it to be.
Click on the Default button. Word will ask if you want to make your choice the default font. Click on Yes.
Holding down the Shift key, click on File menu. Click on Save All.
In the Save dialog box, click on Save, even though you have a blank document.
You will get a dialog box saying that changes have been made affecting the global template Normal.dot, the file that contains all of your basic formatting choices, and asking whether you want to save them.
Click on Yes.
Approach 2: With Word and a new document open, click on Format, and choose Style. Click on Modify.
In the Modify dialog box, click on "Add to Template" to check the accompanying box.
Click on the Format button, then on Font. Make your font choices.
Click on OK. Click on OK again back in the Modify dialog box.
Click on Apply.
Holding down the Shift key, click on the File menu, and choose Save All.
Click on Save. You will get a dialog box saying that you have made changes in Normal.dot and asking whether you want to save those.
Click on Yes.
Approach 3: Using Window's Find utility, locate the Normal.dot file. Write down where it resides. Do not double-click on it to open it from the Find dialog box.
Start Word, then use Open to call up the Normal.dot file.
You'll get a blank document.
Click on the Format menu, then on Font, and choose the one you want to use.
Click on the Default button within the Font dialog box.
A message will appear asking whether you want to change the default font. Click on Yes.
Close the document. You'll get a message asking whether you want to save your changes to the global template. Click on Yes.