Network Resource Unavailable

I'm trying to install the newest versions of itunes and quicktime, but when I try to install quicktime it comes up with the error, "The feature you are trying to use is on a network resource that is unavailable." I've tried uninstalling quicktime and it won't let me. When I click 'ok' it says, "the path 'C:\documents and settings\chudy\local settings\application data\apple\apple software\update\quicktime\quicktime.msi' cannot be found. Verify that you have acces to this location and try agai, or try to find the installion package 'Quicktime.msi' in a folder from which you can install the product QuickTime.
Also, I have multiple accounts on this computer. Could it be possible that there are different version of itunes and/or quicktime installed that's causing the problem?