Thanks David, I greatly appreciate that, the worm found was Win32:Renosa-J. I know you said to keep it in the chest for a few weeks then rescan it but does malwarebytes destroy it immediately if I had it installed. Also I had asked is it possible to trace the origin of such a worm ie what site caused it, I know when technicians work on computers they usually seem to be able to tell what site caused it. Thanks again for the quick and informative reply.