XP HOME Startup Probs - Experts only please?

HI I have a PC Under XP (Home ) that boots to desktop - shows the Background picture - but no icons - no start menu just the desktop picture - Booting in safe mode = same (black background) Safe mode in all 4 corners no Icons no Start menu. Start from XP Home - goto recovery console - run scan disk etc same result - I did see a command A while ago - when booting with an MS DOS (ME) startup Disk something like regfix / f or similar - but cant remember the exact command or syntax - Any one any Ideas ? Thanks