Type about:config in the address bar and press Return.
   A warning page may appear. Click Accept the Risk and Continue to go to the about:config page.
   In the Search field, type print_printer.
   Click the Delete Fx71aboutconfig-DeleteButton button to the right of the print_printer preference.
   Click the Firefox menu at the top of the screen and select Quit Firefox. 

   Open your profile folder:
       From the Help menu, select Troubleshooting Information. The Troubleshooting Information tab will open.
       Under the Application Basics section next to Profile Folder, click Show in Finder. A window will open that contains your profile folder. 
   Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.

   Click the Firefox menu at the top of the screen and select Quit Firefox.
   In your profile folder, copy the prefs.js file to another folder to make a backup of it.
   Open the original prefs.js file in a text editor (such as TextEdit).
   Remove all lines in the prefs.js file that start with print_ and save the file. 

Hi When I try to print emails in the Outlook webpage it takes 1minute 30 secs for the print dialogue box to come up after you press the button. I have followed both steps of Firefox help listed below: '''Reset Firefox printer setting''' Several printer issues can be resolved by resetting Firefox's printer settings: Type about:config in the address bar and press Return. A warning page may appear. Click Accept the Risk and Continue to go to the about:config page. In the Search field, type print_printer. Click the Delete Fx71aboutconfig-DeleteButton button to the right of the print_printer preference. Click the Firefox menu at the top of the screen and select Quit Firefox. When you start Firefox again, try printing the page that you had problems with previously. Note: In older versions of Firefox print.print_printer was the preference name. The old preference name may exist along with the new name. That old preference can be removed by clicking the Delete Fx71aboutconfig-DeleteButton button. Restart Firefox and print a page after performing the reset. That preference won't reappear. The newer preference will only be available. '''Reset all Firefox printer settings''' If the above steps did not work, you may want to reset all of Firefox's printer settings: Open your profile folder: From the Help menu, select Troubleshooting Information. The Troubleshooting Information tab will open. Under the Application Basics section next to Profile Folder, click Show in Finder. A window will open that contains your profile folder. Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox. Click the Firefox menu at the top of the screen and select Quit Firefox. In your profile folder, copy the prefs.js file to another folder to make a backup of it. Open the original prefs.js file in a text editor (such as TextEdit). Remove all lines in the prefs.js file that start with print_ and save the file. In fact, actually I have two Prefs files: prefs.js and prefs-1.js. The printer I am using is listed in the second file prefs-1.js. Any ideas please? Thanks