That one was done with a Microsoft update that incorrectly updated people not using Bing.

How to Remove Bing as Your Default Search Engine and Get Firefox to Work the Way it Used to | eHow.com

http://www.ehow.com/how_5196325_remove-firefox-work-way-used.html

http://kb.mozillazine.org/Keyword.URL

Removing the Search Helper Extension and Bing Bar | Troubleshooting | Firefox Help

http://support.mozilla.com/en-US/kb/Removing%20the%20Search%20Helper%20Extension%20and%20Bing%20Bar

Make Google.com or any other page your home page

https://support.mozilla.com/en-US/kb/How to set the home page

Tools > Options Security [x] Warn me when sites try to install add-ons [x] Block reported attack sites [x] Block reported web forgeries

I was too impatient to wait and a quick Google search revealed that this is a very common problem. I found no one had posted the complete answer but a two step repair did the trick for me. If, like my situation, the standard Firefox Menu Buttons were missing, right-click on the icon in the left corner of the URL box and check the Menu Bar.

Step 1- Bring down Tools, choose "option" click on "General" which lets you choose how things start up. In my case, I wanted the default Firefox with Google page so I clicked "Restore to default".

Step 2- You still have the program that Bing installed, ready at the slightest excuse to take over again. So do not forget to uninstall the search bar for it . Bring up the Control Panel for Windows. Under Programs, uninstall the Bing search bar. There! Doesn't that feel better?

Sometime Bing is not located in the Add/Remove programs section of the control panel.

6 Easy Steps to Remove Bing from Mozilla Firefox:

1. Click on the "inverted triangle" located to the right of the orange Bing icon.

2. Select the option "Manage Search Engines...". (A pop-up window will appear titled "Manage Search Engine List.)

3. Select "Bing".

4. Click the "Remove" button.

5. Select the desired search engine from the list.

6. Click "OK"

All Done.... :-)

Happy Searching...

https://support.mozilla.com/en-US/kb/Search%20bar?s=bing&as=s

I removed the bing install listed in the control panel Programs and Features (Win 7) (add/remove programs in XP) but that didn't remove the bing search from the Firefox(v6) toolbar. Went then to the Extensions selection in Add-ons. The only extension listed was something called StartNow. I selected to remove that extension and Bing disappeared from Firefox.

When I opened a new tab the Bing search would be there. I removed this by using my Windows Explorer to go to C:Programs and looking for the StartNow folder. I opened the folder and found the uninstall application and used it. This removed the Bing search in a new tab.

This insidious bing was making me crazy too. After tryng some slutions posted here, I found an easy one for chrome. Right click in the address bar, click 'edit search providers', reset default!!!

I have the NoScript add-on ans used it to block Bing. I then used the "Manage Search Engines" option and removed Bing as a search option. The irritating browser hijack dialog box is gone (so far). Hope this helps

When I hit HOME, it went to BING, even tho Firefox still knew home = Google. When I entered "www.google.com" in address bar, same thing, went to BING. Finally fixed by: > Control Panel > Internet Options > General (tab), Home Page ... Microsoft had set that www.go.bing.something or other Changed that back to "www.google.com" and problem fixed. Windows XP, Firefox browser, with home page set to google.com.