Hello, I used to have similiar problems with babylon rather then trovi.com but it might work too. Just download AdwCleaner, you'll need to do the setup and everything (don't worry, its not an adware or anything, I still use it and most people recommend it you can always look for feedbacks if you don't trust me).

Click the scan button and then the delete one, you'll need a computer restart but once it did trovi should be gone

Hope it helps !

Download the Mozilla Search Reset {web link} This add-on is very simple: on installation, it backs up and then resets your search preferences and home page to their default values, and then uninstalls itself. This affects the search bar, URL bar searches, and the home page.

Open a new window or tab. In the address bar, type about:config. If a warning screen comes up, press the Be Careful button. This is where Firefox finds information it needs to run. At the top of the screen is a search bar. Enter browser.newtab.url and press enter. browser.newtab.url tells Firefox what to show when a new tab is opened. If you want, right click and select Modify. You can change the setting to;

about:home (Firefox default home page), about:newtab (shows the sites most visited), about:blank (a blank page),

or you can enter any web page or about: page you want.

The same instructions are used for the new window setting, listed as browser.startup.homepage.

See also:

• http://malwaretips.com/blogs/trovi-com-removal/