First off, I open the fonts folder. Then I simplify the whole matter by clicking on toolbar View drop down, and click on the "Hide variations" phrase, (three-quarters down the menu.) Font variations disappear, simplifying the matter. This may be helpful for people with a couple hundred fonts or more.
My XP Home system, seems to let me select all fonts (from Edit drop down in Windows explorer toolbar, once I open the fonts folder), and let me 'delete' from a pop up menu inside the opened fonts folder in right pane (the big one.) Then, it tells me access is denied to one font, so I click OK on that Grey pop up message. The other fonts seem to negotiate themselves nicely under this deletion process, with Windows only deleting the ultimately unnecessary ones (apparently!)
This is after much unnecessary searching on the Internet for real and complete info on fonts saving and removal (how-to, what to keep, how to determine what to keep, etc.) Don't bother: stick with the above for now.
Note: your Word program may add extra fonts to your system.
Also: if leery of this process, you can at least satisfy yourself by getting rid of some more obviously needless fonts, like Gautama or whatever, assuming your system lets you, as per the above.
You can always reload your fonts from some process involving your operating system disc, or perhaps even download them from some location on the Internet, should you decide you need those old deleted fonts back. I just delete them, and don't even bother to make a separate folder for them.
(If you do make a separate folder for unused fonts, for rescue later, if need be, I wouldn't put them in a sub folder of the regular Fonts folder. I'd rename it something entirely out of its alphabetical realm. Maybe you could store them in Program folder, away from the Windows operating system folder entirely. That should guarantee Windows from doing any possible searching of any possible kind, in the extra folder for unneeded fonts, and slowing your system down, especially at boot up. This is the whole point of this 'negotiation of the fonts' problem.)
(Note also that apparently Windows needs some surplus and apparently useless fonts, because it does "other things" with them. This is researchable on the Internet, for those who need to know.)