okay. we're going to completely scrape out all your existing QuickTime and itunes and do a careful staged reinstall.
preliminaries
download and save to your hard drive copies of these two installers (don't install them just yet):
Quicktime 7.1 Standalone Installer
iTunes 6.0.4.2 Installer
... and download
and install the Windows Installer CleanUp utility (we're going to use it during the uninstall stage of proceedings):
Description of the Windows Installer CleanUp Utility
uninstall phase
switch off antispyware and antivirus applications prior to any uninstalls.
use the complete uninstallation instructions in the following document to completely remove your QT and itunes program files:
Trouble installing iPod, iTunes, or QuickTime software in Windows
if you run into trouble on one of the installs, use the Installer CleanUp utility to clear the installation configuration for that program, and then use the uninstallation instructions as a guide for manual removal of any leftover program files and folders.
even if you don't run into trouble, after you've completed the uninstalls run CleanUp
anyway to check for any leftover QT or itunes installation configuration information. if you find any, remove it.
reboot the PC.
reinstall phase
switch off antivirus and antispyware prior to any installs.
first install the standalone QuickTime. reboot.
then install itunes. reboot.
do those installs go through okay? if so, does your itunes launch properly afterwards?
love, b