Just an update.
I have just uninstalled and reinstalled the game. It again downloaded all the system files and put a shortcut on the desktop but asked me to log in as administrator.
Once I had logged in as administrator it said there were compatibility issues with the game. I right clicked on the shortcut, selected properties and compatibility and changed it to Windows XP. I again tried to launched the game and it came with the same compatibility error and suggested I used the compatibility troubleshooter.
I tried changinge the compability to Windows Vista, clicked Apply and OK and again doubled clicked on the Dungeon keeper shortcut.
Again it didnt play and said there were compatibility issues.
Just wanted you to know specifically what I had tried.
Thanks,
Nigel