I don't know how they were re-enabling their extensions. I got rid of the Kaspersky extensions as follows: In the Kaspersky menu, I went to Settings > Protect

I don't know how they were re-enabling their extensions. I got rid of the Kaspersky extensions as follows: In the Kaspersky menu, I went to Settings > Protection > Web Anti-Virus > Advanced Settings, and unchecked "Automatically activate application plug-ins in all web browsers". Though Kaspersky's settings refer to plug-ins, this actually disables the extensions, not the plug-ins. You can't choose which of their 3 extensions to enable or disable; it's all or nothing. I also disabled Kaspersky's Web Anti-Virus, which may or may not have been necessary to the procedure. As to how they were re-enabling plug-ins, I found a comment on the Kaspersky forums that seems informative and I'll quote here: FF stores all its settings in prefs.js file but user.js file serves a different purpose.[1] A user.js file is an alternative method of modifying preferences, recommended for advanced users only. Unless you need a user.js file for a specific purpose you should use about:config instead. The user.js file does not exist by default. Once an entry for a preference setting exists in the user.js file, any change you make to that setting in the options and preference dialogs or via about:config will be lost when you restart your Mozilla application because the user.js entry will override it.[2] So, here is what KIS does: after installation it creates user.js file in your Firefox profile and writes a couple of preferences there that activate Kaspersky plugins. As the result, even if you disable the plugins in FF settings, they will be enabled after restart.[3] [1][3] http://forum.kaspersky.com/index.php?showtopic=301934&st=0&p=2282289&#entry2282289 http://forum.kaspersky.com/index.php?showtopic=301934&st=0&p... [2] http://kb.mozillazine.org/User.js_file http://kb.mozillazine.org/User.js_file I personally got rid of the Kaspersky plug-ins as follows: - Saved my Firefox bookmarks - Uninstalled Firefox - Removed my FF profile (in Window 7, it's c:/Users/<username>/AppData/Roaming/Mozilla/Firefox/Profiles/*) - Disabled Kaspersky - Reinstalled Firefox - Created a new profile in Firefox (FF will ask you if the profile is missing) - Restored my Firefox bookmarks - Re-enabled Kaspersky