Hi Growler. Sorry not to have got back sooner, but have only just managed to get the pc to come on for the first time since yesterday. Actually, fiddled around with some wires at the back, so, who knows, it may have been a loose connection, but not holding my breath !! No, son hasn't fathomed it, but lets hope I have. Would like an answer to your question about returning the pc to an earlier date, but somehow I don't think that works - think I read it somewhere. Hopefully someone else may know. Thank you.
Silas