This video shows you how to disable the automated spell checker in Mozilla Firefox. The spell checker is supposed to be a great feature in Firefox, but lot of people find it annoying. The spell checker helps you correct your writing mistakes by underlining the misspelled word with red. You can easily disable it by opening the Tools tab in Firefox and selecting Options. Then, go to the Advanced tab in the popped-up window and uncheck "Check my spelling as I type". That's it! Good Luck!