Chances are you won't get everything by just uninstalling Firefox. The original "program" that carried that garbage onto your PC needs to be completely removed, or it may just re-infect you all over again. See this - http://malwaretips.com/blogs/remove-istartsurf-virus/

mipen said

I have tried every possible method, but it just won't move. What if I uninstall Firefox, and reinstall?

After I did the process with the three browsers, istartsurf disappeared. I downloaded and ran Adw cleaner, and Malwarebytes. Only problem when I tried to statr Firefox, it crashed. Everything OK now, thanks,

Regards, M.C.