I'm having problems with Windows Update, and am unable to update to Vista SP1 - basically it fails to install. I've heard of a solution, but am not certain how it will affect the system, so, to be on the safe side, I'm of the opinion that I should deactivate my license until fixed.

Looking at the License Administrator, I have an option to ‘Return License’ when Houdini-Apprentice-HD 9.1 is right clicked. No option is available for Render -NonCommercial 9.1, or the Houdini-Master-NonComercial 9.1. Do I just return the one available, or are there more steps needed to be taken?

There is a bug in Houdini 9.1.124 that prevents returning of the Apprentice licesnes. This bug has been fixed in Houdini 9.1.140, so if you would like return the Master-NonCommercial and Renderer-NonCommercial, you will need to upgrade to the latest Houdini version.

You can do it by simply downloading and installing, for example, Houdini 9.1.187 from the Support > Download menu on this website. Just scroll to the middle of the page, to the daily builds which are just below production builds section. There you should see the link for downloading various Houdini versions.

Once you install Houdini it will run right away since you still have the NonCommercial licenses installed. You will be now able to use License Administrator to return these two licenses.

Thanks Rafal, I'll give it a go.

John