itunes won't install

I'm trying to install iTunes 10.5 but during the installation it gets stuck on
Status:

So there's nothing after status. And then after a few minutes it just says:

The installer encountered errors before iTunes could be configured.
Errors occured during installation. Your system has not been modified.

Please run the installer again, or clik Finish to exit.

So I've done this a few times but still won't work. Any suggestions?