The initial help was my brother administrator for a large network with years of experience, who was visiting at Christmas but didn't have any of his software with him. He removed what he was able to root out manually. It cleared up a lot, seemed to be OK at first, but then hiccups started.
I'll try GMer later on, got to get outside now....
Thanks for all the assistance, by the way. Enormously helpful and educational, I really appreciate it.