How Do I Disable Firefox to Download Flash Player?

1. Type 'about:config' (without quotes) into the address bar at the top of the Firefox window and press 'Enter.'
2. Click the 'I'll Be Careful, I Promise!' button on the warning page.
3. Type 'plugins.hide' (without quotes) into the 'Filter' box at the top of the about:config page.
4. Right-click the 'plugins.hide_infobar_for_missing_plugin' preference and click 'Toggle.'