The files listed here are all ZIP files, which contain a REG (Registry) file. Each of the REG files contains the default settings for the file extension indicated.

So I went and downloaded Netscape Communicator 4.something to test some of the JavaScript I'm writing for Memetreams. After shuttering at how arcane installers were back-in-the-day, I find that the front page of Memestreams crashes it. I figure the some of embedded Flash for Google/Youtube videos might be doing it, so I go into the browser's preferences and remove every file association hoping it will not spawn the Flash player (which in retrospect wouldn't have worked anyway... stupid object tag GUIDS...). Unfortunately, this actually killed the file associations not for the browser, but for Windows!

Windows XP File Assocation Fixes