When I start my pc , I get my wallpaper , but that's it , it has no icons/programs/, the only thing I see is my wallpaper, and my mouse, and when I do right mouse click I also can't see the window it makes , and alt+ctrl+del , doesn't show/work either.
Thanks for your suggestions I will try them out and get back to you.
I have had an IT engineer here for 7 hours today and he has never seen this before. He tried all sorts but it has defeated him and I am so upset I can't begin to tell you. He has cloned the data from the machine so at least I know that is safe.