I'm not sure of the safest way to remove it, but two thoughts come to mind:

(1) Another program might be protecting it. In the Windows Control Panel, Uninstall a Program, after the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This may help in finding companion programs related to Incredibar that are flying under the radar. Take out as much trash as possible here.

(2) You may be able to disable the related add-ons in Firefox for immediate symptom relief.

Open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Set nonessential and unrecognized plugins to "Never Activate".

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions.

Often a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

(3) After removing or disabling unwanted extensions, you can regain control over your preferred search engine using the search bar menu. This article has more info: Search bar - add, change and manage search engines on Firefox.

Any progress?

Here's a little more info on Web Assistant: http://forums.cnet.com/7726-19703_102-5322355.html?tag=posts;msg5322355

You might want to try some of the cleaning tools listed in our support article: Troubleshoot Firefox issues caused by malware. They might be able to handle the removal automatically.