So I start to install quicktime 7 and about halfway through I get this message, "Error 1721. There is a problem with this Windows installer package. A program required for this install could not be run. Contact your support personal or package vendor," followed by this message, "Error: -1603 Fatal error during installation. Consult Windows Installer Help (Msi.chm) or MSDN for more information.
So I try to download a new Windows installer, and it installs fine, but I get the same message when I try to install quicktime again.