Not the Java/possessed website

Updating Java didn't drive out the deamon that's possessed my website. Where else could the problem be coming from ? I have mentioned that the website did work with the "zoom" for a while then mysteriously stopped. Maybe a Microsoft update ? or my dial up connection. My web designer is at a loss to explain this except that there is a small percentage of computers that don't work like all the rest and mine is probably one of them !  What's plan " B"  ?