|Advanced Configuration Options
Besides the configuration options available under the Tools menu, typing about:config in the address bar will open up a Firefox configuration file. The good news is your cannot mess anything up permanently. Changes made to about:config are stored in a file that is not present by default; user.js in the Mozilla profile folder. To go back to the bone stock configuration, simply delete this file and it is like the changes never happened.
To locate the directory housing the configuration file:
On Windows XP/2000, the path is usually %AppData%\Mozilla\Firefox\Profiles\default.xxx\, where xxx is a random string of 3 characters. Just browse to C:\Documents and Settings\[User Name]\Application Data\Mozilla\Firefox\Profiles\ and the rest should be obvious.
On Windows 95/98/Me, the path is usually C:\WINDOWS\Application Data\Mozilla\Firefox\Profiles\default.xxx\
On Linux, the path is usually ~/.mozilla/firefox/default.xxx/.
On MacOS X, the path is usually ~/Library/Application Support/Firefox/Profiles/default.xxx/.
*Obtained from Texturizer.net
Some of the commands listed are not listed in the user.js file. It is probably a better idea to create the file manually (Windows users can create a text document and rename the file and extension).
If you want to copy and paste the contents into the user.js file just go right ahead. For those editing through about:config, you should only be concerned with the contents inside the " " and after the comma- user_pref("key",value); as the user_pref and the brackets, quotes and semi colons can all be ignored.
Disabling New Windows
Firefox does block pop ups but there are links that like to open new Windows to the chagrin of some users. To disable webpages or links from opening up new windows modify these 3 settings -
This will not be perfect though it should result in fewer open Windows due to links. There is a pure tabs mode with an extention to Firefox, something that we will talk about later on.
Show Pictures As They are Loading (IE Style)
This is a psychological thing more than anything else. By default, Firefox uses placeholder images by leaving image locations blank or with the white box and x combo. Changing this value will result in the load as it goes approach as with IE