I was reading my help files this evening and ended up coming across something that might be the master reset. I havn't tried it but perhaps you want to.

It says that all settings are saved in a directory called "prefs", everytime you exit out of Maya. If I read it correctly, you can rename that directory (folder I think) to something else. Then the next time you open Maya, Maya will create a new directory. I think everything will be at default settings. Then if you want to go back to your previous settings, rename the previous directory back to "prefs" (or whatever it was). Then when you open Maya, you're previouse settings are restored.

Hope this is the answer you were looking for.