@Peter-Corstiaans Hello. This isn't Magix customer support but a user forum and we are all users like you. But maybe we can give advice.
I assume you see a pop-up message after starting your computer? This appears if you don't opt-out of installing the Magix Update Notifier during the installation of Magix software.
You can simply uninstall the Magix Update Notifier in the Windows Apps settings. That should get rid of these pop-ups.