Try to disable the MSN® Toolbar (Tools > Add-ons > Plugins) that shows in your plugins list.

See Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems

Thank you. I could not uninstall the plug-in as you suggested without firefox freezing, but I could uninstall the msn toolbar from the control panel, after closing firefox, and that took a little while, but it worked. I opened firefox after the uninstall and bing was GONE. thank you again for the suggestion and with this little tweak it worked.

Or rather, the image I attempted to attach! Frustrating upload.http://tinyurl.com/3636u7n Links are cleaner.

I followed exactly what you did and it worked out beautifully!

Thank you, I offered a thank you but the posting of the comment fell through, excuses and apologies.

I haven't been able to uninstall the Bing tool bar because there is no reference to it in either Add Remove Programs on my XP or in the addons or plugins in Firefox. I was able to hide it by going to View, Toolbars and unchecking Search Tool bar.

I, too, had this problem, though I am using IE8 my answer is still good for those of you using Firefox.

I'm running Win7 Home Prem. and I had removed Bing as the Search Provider in IE, and then went to Programs & Features (old Add/Remove Programs) and saw Bing Bar listed there. I clicked on it and then clicked on Uninstall and it took me to another page where I was offered to uninstall it by clicking on Continue. When I clicked on Continue, I received a message that I should close all browsers. There were no browsers open; so, like some other reports on this dilemma, Bing seems to have an opened file making it seem as if there is an opened browser.

My solution was this - and please don't leave this step out. You may have to go back and Import the registry file in case you delete the wrong key. Go to the Start Button and type regedit in the Search window just above the Start Button and hit return. When the window opens the Registry, go to File and in the pulldown click on Export. This gives you a chance to save the existing Registry file before you progress to the next action. It defaults a location in My Documents and wants you to assign a file name. I gave it: Registry 3-20-2011 (don't use forward slashes to separate mm-dd-yyyy - use hyphens).

After the Registry has been saved, click on the top folder in the Registry which is Computer to highlight it, and click on Edit and then Find. Type in: Bing Bar in the search window there and click on Find Next.

Each time it finds a hit, use the Delete Key on your keyboard to delete the Registry Key in the left pane. Hit F3 to find the next occurence deleting the Keys each time.

After it has searched the entire Registry, you'll get a message to the effect that the search is complete. At that point, it is safe to close the Registry.

There is one remaining step. You have to manually delete the folder under C:/Program Files/Bing Bar Installer in Windows Explorer. When you click on this folder you'll notice several sub-folders, but don't have to delete them individually. Delete the main folder and your work is done.

Don't be timid if you've never worked in the Registry, but then don't get over confident and mess up, either.

Just found this website and explains how to remove Bing:On XP, go under control panel, add and remove programs, it’s listed under “Search toolbar”, not Bing toolbar. Then remove it. You will see Bing’s name as you remove it.

Found Search toolbar but did not see Bing when deleted

I cannot thank you enough for this posting! You won't believe how many times I have tried to remove the (blanking) bing toolbar; to the point of doing a system restore... ouch! I have used these instructions many times over the years; much to my delight. Thank you very much. Regards, Markm.

You can find the "Instaled Updates" under "Program and Features" in windows 7.

Find and remove KB 2549984.