|A few suggestions:|
How much time do you give it before giving up? Someone dropped off a computer that was doing that but it was just because it was booting up extrememly slow (too little ram and too much junk loading). It took at least 5 minutes for the icons to show up.
I'm not sure this will help but you can try it. If you can open 'taskbar and start menu':
check 'lock the taskbar'
uncheck 'auto-hide the taskbar'
check 'keep the taskbar on top of other windows'
uncheck 'group similar taskbar buttons'
and farther down:
uncheck 'hide inactive icons'.
What happens if you boot to safe mode?
If you can get to windows system restore--either through normal or safe mode--you can try that, choosing a date from before the problem started.