So I have spent the last 3 hours, googling, reading, searching, downloading, restarting etc, and still am no better off. Basically when I try and upgrade to iTunes 8.0.1, it gets to the end of "copying files", then does the "rolling back" thing. Then I get an error saying it has failed to install. Currently I am on version 7.6 of iTunes. Things I have tried: Uninstalling quicktime - no help Uninstalling itunes - will not uninstall which is weird Installing iTunes 7.7 x64 - same problem as 8.0.1, won't install Installing iTunes separate installer - same problem Installing Quicktime using separate installer - gets too "initializing file types" then completely freezes, yet seems to (maybe only mostly) install. Restarting about a dozen times in between different installs/uninstalls. So I am out of ideas, and REALLY hoping someone here has had the same problem, and knows of a fix?