I haven't figured out how to change it but at least I figured out why it showed up on my browser in the first place. I installed a toolbar (in my case the playdom toolbar) that puts the search box on a new tab when you open one via the plus button on the tab bar however after searching the forum I can remove the box and re-add the box but I cannot change it from bing to google which I want to, so if anyone figures that out please let me know.

To Do This U Have To Follow Two Simple Steps

1: In Ur Browsers Address Bar Type "about:config". Without The Coutes. 2: Accept The Warning "I Will Be Careful I Promise". 3. Then In The Filter Box Search For "keyword.url". 4. This key has no value by default i.e it uses the standard Google search option that always opens the search results page. Now If Something Have Changed This Value Then U Can See The Page Address There. U Have To Change It. Now Double Click The Parameter And Paste The Any URL Given Bellow As Ur Choice.

   * Google Browse By Name: http://www.google.com/search?ie=UTF-8&sourceid=navclient&gfns=1&q=
   * Google I’m Feeling Lucky: http://www.google.com/search?ie=UTF-8&btnI=&q=
   * Google Default: http://www.google.com/search?ie=UTF-8&q=
   * Yahoo Search: http://search.yahoo.com/search?p=
   * Bing Search: http://www.bing.com/search?q=
   * Ask: http://www.ask.com/web?q=

Go to your plug-ins and uninstall useless toolbars, that should work

I have followed this example, however, Bing still comes up when you open a new tab. Any other suggestions? There are several other bing lines in keyword URL as well?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

• Open the about:config page via the location bar and do a search for bing via the Filter at the top of the about:config page.
  
• Reset all bing related prefs that appear bold (user set) via the right-click context menu to their default values.

You can also check:

• https://support.mozilla.com/kb/Removing+the+Search+Helper+Extension+and+Bing+Bar