It sounds like you have a third party program that has taken over your search engine, home page, and/or the default new tab page. Fortunately, this can be remedied easily:

1. At the top of the Firefox window, click on the Firefox button (Tools menu in Windows XP), and then click Add-ons. The Add-ons Manager tab will open.
2. In the Add-ons Manager tab, select the Extensions panel.
3. Select the toolbar you wish to remove.
4. Click the remove button.
5. Click "Restart now" if it pops up. Your tabs will be saved and restored after the restart.

After Firefox restarts, install the Search Reset Tool. This will remove the rest of the traces of this program from your Firefox.

For further information, please read Remove a toolbar that has taken over your Firefox search or home page.

Use anti-adware program. Adwcleaner, Adaware, Spybot S&D - these should detect and remove it. The instructions for IE should partially work - you will have to uninstall something from control panel (most likely).

Another way to access the Troubleshooting Information page, if you like, is to type or paste about:support into the address bar and press Enter.

What were you hoping to find or do on that page?

Here is the ONLY way to get rid of it. first this thing is dl'd if you make a misclick on an infected website also from pop-ups. I just figured out how to get rid of it today and I have seen immediate improvement in my computer and browsers performance.

Attn people, Go through your program (add/remove is easiest) files looking specifically looking for a program called Sendori, made by Sendori Inc. if you have it you ARE at risk. this is a PUP (potentially Unwanted Program). This program is known also as a browser hijacker also classifies as adware and malware.

The symptoms of an infection are underlined words on web pages, slow and lagged web browsers. adds that popup on the pages when you mouse over the underlined words. this program is also known to exploit your firewall and open ports for potential viruses and hackers. it took me almost 6 months to pinpoint the infection and the "application" that it was downloaded with. Misclicks can cost you alot. if you have this program you need to remove it ASAP! also remove all registry entries with a trusted cleaner tool I personally use CCleaner (crap cleaner).

from there you NEED to reset your browser or it will come back and it will drive you insane. every browser has a specific way of doing it but they are all similar, you will loose your addons like scriptish and other things like that. you keep your favorites and cookies, but everything is reset. problem fixed. you win.