I had a virus on my computer a few days ago. It was causing a completely unrelated problem. It seems that I have gotten rid of the virus, but now all of my browsers (IE, Firefox, and Opera) will stop working sporadically. The only way to fix it is to do a hard power down (my computer wont let me do a proper shut down, I have to turn it off manually) I dont know if this is another virus that is causing the problem, or if the virus stripped something from my computer vital to the browsers function.