Recently my firefox was hijacked by ICQ. And every search through the address bar returns to the ICQ search engine. Even removal of related add-ons won't work. After digging up the web for a solution, here is a simple way to reset the search facility.

1. On the address bar, type 'about:config' without quotes.
2. Locate keyword.url
3. Right click on it and reset.

You may also wish to remove ICQ search through 'manage search engines'.

If you insist on using ICQ, get lite here.