Q: whem installing itunes i get this message "this installation package could not be opened. Verifiy that the package exists and that you can access it, or contact the application vendor to verify that this is a valid windows installer package"

This is a user to user support forum. You won't get an official response from Apple here. You've added a "me too" post to a four year old thread so chances are that you don't really have exactly the same issue even if you have similar symptoms.

What is the exact error message you get?

Is Windows completely up to date?

Have you tried clearing your browser's cache and downloading a fresh copy of the installer using the direct links?

tt2

Ok, I understand. The OS is up to date, drivers too.

Try the section Install missing components.

tt2

Thank you for your post. I don`t have anything from iTunes because it does not want to install in first place, so from where to have that registry or folder? I don`t have anything from apple installed. Thanks

If you install the components one at a time using that method do they all install? If not are there any error messages?

tt2