Thanks for the replies, I've tried all the suggestions above but none seem to work
I can't even get the blasted thing to start in safe mode. I'm just hoping it is not some malicious add on my Son has downloaded for Minecraft.
Anyway I have a friend who is a bit of a computer whizz so I'll take it over to his place tomorrow to see what he can do with it. If he can't get it resolved then it's back to the shop with it as it's still under guarantee.