I've downloaded the 4.1 update for Cubase Studio 4.

When the installing progress bar has got to around 27%, a box pops up with the following message:

"The upgrade patch cannot be installed by the Windows Installer service because the program to be upgraded may be missing, or the upgrade patch may update a different version of the program. Verify that the program to be upgraded exists on your computer and that you have correct upgrade patch."

I bought Studio 4 only a few days ago specifically to take advantage of the Vista compatibility offered by the 4.1 upgrade. I've never actually used version 4.0, only installed it, got my software key licence and then registered online. No previous version of Cubase has ever been installed on this computer.

Is there anything I can do to resolve this issue?

I'm using a Windows Vista Home Premium system.