Hi Freda
Im not a techy so cant actually help you on the virus thing, but I downloaded that update at work, and although the computer worked as usual, it wouldnt go on the internet at all. However my IT support told me that this new Explorer is full of little quirks, and if I were to physically pull out the electric supply cable to the router, and then put it back in, it should then work OK - and lo and behold it did!! Apparently loads of people had problems and he was busy sorting them all out.
I know this doesnt help your problem, but you are not alone
Lin