itunes wont install update or uninstall

when the update for itunes 7.6 came out i noticed that it would not install the update, giving me an error message to try again later. i trace the problem to the registry (see screenshot of my error). i have tried everything i can think of. i have tried to give admin rights to that key but the key is corrupt. i will put another screenshot of the error i get when i click on the regkey that is having issues. i have tried installing itunes and quicktime separately too. any help will be great! dont be afraid to ask me questions as well, i will gladly answer. i have an aim and msn name if that would be quicker.