I have Windows XP. When I try to update iTunes it can't uninstall old iTunes. When I try to uninstall manually it says iTunes 10.5.2.11 is corrupt now ITunes won't run on this od version on my PC.
I would recommend uninstalling iTunes and all of it's components in the specified order of the first article, then attempt a reinstall of iTunes. If you receive any error during the uninstall, see the steps in the second article below for any component giving you the error.