Tried everything and more suggested on here.
I think I have finally gotten rid of it. Been 3 days now since popping up. Had to go out and buy Norton Internet security, seems to be the only thing at the moment that will get rid of it.
I'd been reluctant to have Norton on my pc as in the past it has slowed things and taken over the pc, now (fingers crossed) it seems to be ok.
Hope nobody else gets this as it is a real pain in the rear to get rid of.