This is caused by a worm that my girlfriend had on her PC, it Disables CMD, TASK Kill, and usually Reg edit! run an online virus scan using Trend micro house call, it should find it! click here PS.Trend might not be able to remove it but type in the name of the virus on the web and it will tell you how Please note that the worm might disable Task Manager so Google & download a free programme called "Kill box" and terminate its running process! If you cannot get into the registry then Download Hijack This find the values and delete it!
You were right on Ben regedit does nor work either. I have run SFC in the hope that it would restore things but alas not, does anybody know how I can restor my system as sistem restore does not go back far enough.