I have just fixed, after many hours of ploughing through the web, a virus that prevents you from using any web browser (IE7, FireFox) to go to anti virus sites. All other sites were accessible. The virus even blocked sites that offered assistance to removing viruses. The infected file was mswsock.dll which is part of the Windows Socket API that interfaces software to the internet. I solved the problem by copying the file from a working OS into the \windows\system32 and \windows\SoftwareDistribution folders. What surprises me is that Nod32 doesn't pick up on this type of virus. Is this something new? I would have thought Nod32 would flag a change to this kind of file.