How do I stop Firefox from uploading the Google Toolbar every time I open it?

Every time I've opened Firefox today, it's announced that Google Toolbar has been downloaded. I've uninstalled it and re-opened a Firefox window three times now, but every time I go to re-open a window, it tells me that I've got the Google Toolbar again. How do I stop this?|||I believe that Firefox has an agreement with google to run their search window in the top right corner of the browser. That's why it's free. Have you tried the Opera browser?