I usually run firefox but until recently have not been able too. I have been attacked by a bunch of viruses and spyware when I was updating my McAfee as my firewall was left down. I now cannot get firefox to work and my Internet explorer is all that works but is riddled with viruses, hijacking attempts and un authorized pop ups and redirections. I have tried re-installing firefox but it still does not work even though its listed as my main browser and not IE. All the viruses come from explorer and are "browser helper objects" installed to work with IE. Is there anyway I can fix this and get back on firefox? My Mcafee and avg wont remove the viruses either and the trojan downloader continues to keep the viruses on my computer after the quarantine/removal after scans. What can i do?

You hit the nail on the head when you mentioned browser helper objects and many times they come with toolbars. I have Google Toolbar on my XP machine and I really shouldn't even have that. I would uninstall them for now if you have any. You can always download them again. That might not get rid of all the viruses but it's a start. After that, update any spybots and anti virus programs and run them. If that doesn't fix it, run Hijack This. Check the processes on www.processlibrary.com if you aren't sure of what you see.