The Microsoft Office 2010 suite uses Calibri 11pt as default font. However, users can easily change the default font style, including size, letterface and color. The font you set as default will be used for all new documents, however you can still change it on a per-document basis.
To modify/customize default font in Word 2010
Open Word 2010. Open a new document (File > New). Press Ctrl-D to bring up the font style dialog box.
You can modify the default font size, typeface, style, color etc. Once you’re done, hit Set As Default, then press OK.
Restart MS Word for the new default fonts to take effect.