How to Disable plugin-container.exe, Plugin Container for Firefox

open Mozilla Firefox and in the address bar type: about:config

double click to set the following lines to false, and restart firefox. you are all set!

dom.ipc.plugins.enabled;false
dom.ipc.plugins.enabled.npctrl.dll;false
dom.ipc.plugins.enabled.npqtplugin.dll;false
dom.ipc.plugins.enabled.npswf32.dll;false
dom.ipc.plugins.enabled.nptest.dll;false