Quicktime seemed to have gotten very confused on my XP box. It seemed to be only partially installed and would not work nor uninstall. The uninstall failed trying to locate a file in my personal temp directory (which had been cleaned). CCleaner failed to remove it and instead generated an MSI Installer error. The solution was to download and install MS Installer Cleanup utility. Run it and select Quicktime. Then re-install QuickTime.