The fonts included in Windows aren’t free for you to use with whatever you want, however you want. Unfortunately, font licensing is a complex subject and also can be very expensive. To stay within what is legally allowed, you should either create and use your own font or download a font that’s free from royalties and has a license that allows you to use it for commercial purposes.
For more information, see here for Microsoft’s explanation of the subject. In particular, these questions and answers:
Can I embed the fonts into a game, application or device I’m developing based on the document font embedding permissions?
No, document font embedding permissions relate to embedding fonts in documents only, not embedding fonts in games, apps and devices.
If I convert the font into a bitmap font can I include that in my game or app?
No, converting Windows fonts to other formats does not change the rules around embedding or redistribution, and format conversion itself is not allowed. Many Microsoft supplied fonts are available for app and game licensing through the original font foundry or Monotype.
Can I include graphic files (eg. GIFs, PNGs or JPEGs) I create using the fonts in my game or apps, say for a logo or banner?
Yes, you can (provided you’re using a product that is not specifically licensed for home, student or non-commercial use). The graphic file must be an image of a word, phrase or passage of text. Converting the font to a bitmap font (where each letter is treated individually) is not allowed.