I have created a .js file for changing preferences in the about:config window. I know my placement of the file in the Mozilla Firefox\defaults\pref folder is correct because 99% of my settings take hold after I drop in the file. For some reason the following preference does not want to change: pref("dom.ipc.plugins.enabled", false); I have tried everything that I can think of to get this setting to change its default value but to no avail. Any help would be greatly appreciated!