Many thanks.  First chance I have had to get on computer since last post.  Son has solved the problems and we have both told oH what will happen to him next time he is bored and wants to play something if he does not consult first!. 

Bing had already beed uninstalled but was still there, son has now uninstalled loads of stuff he (and I) do not recognise.  Internet explorer that wouldn't even boot up for the last year is now working and everything has reverted to normal.  All he needed was to know where what I was complaining about came from and the rest of his uninstlling cascaded from there. 

We have loads of protection so that wasn't a problem.  Thing had been invited in!.  Flash has been updated on Chrome and computer was flying.

Thnk you.