Try reading this first:
http://support.microsoft.com/kb/936648/en-us
When you install iTunes, right-click on the installer program and selecting
"Run as administrator".
"mike" wrote:
> Hi
>
> I have recently received several messages when trying to download software
> (e.g. iTunes) that "The system administrator has set policies to prevent this
> installation".
>
> I am running windows vista home premium and I am set as the administrator
> (with no other users registered). Can anyone tell me how to change these
> settings as I can't seem to find how to do it myself.
>
> --
> cheers