Fonts Folder
The Fonts folder is merely a folder on your hard disk (specifically, WindowsFonts). However, when viewed in Explorer, it's configured to display a list of installed fonts instead of a list of the contents of the folder.
To view a preview of an installed font, just double-click its name. To delete a font, just delete it as you would any file (press the Delete key or drag-drop it into the Recycle Bin). To install a font (as long as it's one of the supported types), just drag-drop it into the Fonts folder. Supported typeface formats include TrueType (.ttf), Adobe Type 1 (.pfm and .pfb), OpenType (also known as TrueType v2), and ugly old raster fonts (.fon) used in early versions of Windows.