Windows includes a set of raster fonts. These are the fonts that you commonly use in the various parts of the system. They come in specific sizes. For example, you’ll find MS Serif in 8, 10, 12, and 14 point sizes. Although you can use these fonts for any of your applications (and XP will scale them), they always look best in their supplied sizes. If you scale them more than one or two point sizes, they will become jagged looking. Here is a list of the Windows raster fonts.
MS Sans Serif