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1. Select the Firefox menu, then "About Firefox."
   
   
   
   
2. In the display window, the version will appear below the word Firefox
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Windows

Newer versions of Firefox

1. Click the Menu button in the top right corner
2. Select the Help option at the bottom of the menu that appears - this is denoted by a question mark
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3. Select "About Firefox"
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4. A dialogue box will appear and the version number will be located underneath the word Firefox
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