As others have said, you will have to remove them from your computer.
You can do this by going to:
Start
Control Panel
Appearance and Personalization
Fonts
(On windows anyways)
There you can also HIDE fonts if you don't want to uninstall them or if they're defaults or whatever.
This way you can hide all the fonts you don't want to see, and then later unhide them if you need them for a word document or some other project.