Q: How do I "delete" my preferences on Windows or Mac?

A: If Maya starts acting really strange, sometimes there's nothing for it but to reset the application to default preferences.

On Windows, the prefs folder can generally be found as C:\Users\YourUsername\My Documents\maya\2013-x64\prefs (or whatever version you have).

On Mac it is /Users/YourUsername/Library/Preferences/Autodesk/maya/2013/prefs (or whatever the version is).

The best way to kill the prefs folder without losing your preferences completely, is to just rename the prefs folder as prefs_2012-07-09 or whatever date you want to give. When you restart Maya the next time, a whole new set of preferences will be generated, and hopefully the buggy behaviour will be gone.

Note: You don't typically have to reset the whole folder, usually killing the userPrefs.mel file is enough.