I have a Sony Vaio with Vista operating system. I have lots of problems accessing websites - about half of them do not work. Often it is the main home page that doesn't work but the sub-pages do ie if I type www.***.com it doesn't work but going to www.***.com/*** I get the page and am then able to go back to the home page. Someone told me it might be a virus - any ideas? It is extremely annoying.