Problem with ANY Steinberg installer - Installer window disappears

Hi everyone, I’ve just purchased Cubase Pro 12 as I wanted to update my Pro 10.0.6 so I downloaded all the apps and stuff but apparently nothing’s working!
I’ll be more specific. I downloaded Pro 12 first and the Download Assistant didn’t install it automatically. I tried doing it myself but the actual installer starts and then it disappears completely. I managed to install it anyway with the actual individual installer and it went fine. The only problem then was that none of the updates for Retrologue, Groove Agent, etc installers were working, so I thought I would try to remove them first but still no luck. I run all the Microsoft troubleshooting software but still the same issue.
I downloaded again Pro 10 and its update 10.0.60 and it seems their installers are not working either so now I’m stuck. No Pro 12 or at least no full Pro 12 and I can’t install anything else. Can you please help? I’m stuck

Welcome to the forum.

This is likely caused by a damaged Windows registry. This could have been caused by a virus or an overly eager clean-up app (CCleaner, etc…).

The simplest way to fix this is to perform a clean Windows reinstall. If you would like to avoid having to do that, you can try performing a “deep” uninstall of all Steinberg products by using a third party uninstaller such as Revo Uninstaller or Advanced Uninstaller. They provide options to delete the registry keys and leftover files associated with the programs.

Once you’re done, run the latest version of the Steinberg Download Assistant. It should automatically install the eLicenser Control Center, Steinberg Library Manager, and Steinberg Activation Manager.

You have to be kidding. Immediately, the client is blamed for having a faulty computer. After all the client has suffered so far, he/she will now go to a huge amount of work and possibly extra expense to troubleshoot this?
I have a completely rebuilt and robust Windows computer and I am in appoximately the same boat, i.e. using your alternate download site to manually install my Cubase upgrade after having gone through it all for the initial version purchase.
Why has your installation gone so badly?

Dont get me wrong, I love this product ! it is just very disappointing after the humiliating process of buying the product, to find that you need major computer experience to install it.