Firefox 3.6 for Microsoft Windows

1. Click Tools menu
2. Select Options
3. Select the Content tab
4. Uncheck  Block Popup Windows
5. Click Ok

Note: if the Tools menu is not visible, press the Alt button on your keyboard to show the menu bar.

Firefox 4.0 thru 28.0

1. Click the orange Firefox button at the top left of the browser
2. Select Options
3. Select the Content tab
4. Uncheck  Block Popup Windows
5. Click Ok

Firefox 29.0 - 55.0

1. Click , in upper-right of window
2. Select Options
3. Select the Contenttab
4. Uncheck "Block Popup Windows"
5. Click Ok

Firefox 56.0 and Higher

1. Click , in upper-right of window
2. Select Options
3. Select the Privacy & Securitytab
4. Under the Permissions section, uncheck "Block Popup Windows"
5. Click Ok

All Versions for MAC OS X

1. Click Firefox menu on the top left of the menu bar.
2. Select Preferences from the drop down menu.
3. Select the Content Tab at the top of the window.
4. Uncheck Block Popup Windows
5. Click Ok