Not sure why it's failing for you. The only thing that comes to mind is some sort of registry protection software is preventing the required key from being created.
If you are familiar with the registry, using RegEdit check the contents of :
We have seen this before where the user has one of these anti-spyware programs installed or some boot manager.
Something is stopping Opus saving this information to the system registry. Check what you have installeld and set it to allow Opus to update registry entries.
Thanks for replying. I checked in the registry, and the line which relates to Opus is there correctly, but I am now looking at the second suggestion where the problem could be with anti- spyware software, as I do have quite a bit of this installed, which may be interfering with Opus in some way.