You should do as Spectre says but a tiny different approach could be;
Look up the font-manager software. Then you should uninstall most of the fonts.
Now you can start browsing for fonts through your font-manager software and install and use the fonts you actually want to use. As the fontcollection in use grows, you can start managing them the way Spectre says.
This is how I did it and it works well.
I do not know which software to recommend though, I've been using Adobe Font Manager but I've never been happy about it.
M

rten