I've
deactivated all Microsoft Exchange Services and the following services from Exchange Server Toolbox:
- ClamAV in a Box
- Exchange Server Toolbox
- Exchange Server Toolbox Redis Archive Command Cache
- Exchange Server Toolbox Redis Processing Cache
- SpamAssassin in a Box
Afterwards I did a reboot and checked the state of the services to be sure all services did not run.
Then went into Windows Update. The first update for .NET 4.8 failed but the cumulative update 04-2023 was then installed.
After reboot Windows Update showed success for the cumulative update which was very nice.
Again I rebooted since Windows Update insisted that some installation was still not finished.
After logging in again I started Windows Update one more time and it downloaded some security fix as usual and also .NET 4.8 update.
This seemed to install without any problem and after another reboot all Updates were finished.
Now I compared the list of services which were activated as auto or manual for Exchange Server and for Exchange Server Toolbox and restored the previous settings.
After being sure there weren't any more differences I did a final reboot.
So the state now is that the updates were successful applied and the Exchange Server is running again.
Thank you very much for your help!