When you open a program, usually the "normal" or "default" template opens up and it's already been set up to contain pre-set formatting defaults, including the font. Here is how you do it in Word:

1. If your document already contains text formatted with the properties you want to use, select that text.

2. On the Format menu, click Font.

3. Select the options you want to apply to the default font. If you selected text in step 1, the properties you want will appear in the dialog box.

4. Click Default.

Any new document you open will use the font settings you selected. If you want to know how to change the default font in other programs, see Help in those particular program