Luckily there are applications like FontFrenzy to give a hand, since it can restart your operating system and leave the fonts just as they were when you bought the computer.
Another interesting thing about FontFrenzy is its ability to generate an image of your installed fonts. You can resume this image or restore point at any given time and install all the fonts again if you need to.
From the program interface you can use other features like adding fonts, downloading and saving them in a secure place, deleting them from your system, and so on.
The application is free, but you have to register it after 40 days if you want to keep using it.