Been trying to install the Music Maker Premium 2021 Edition. I have tried totally removing Music Maker from the PC. Each time I attempt an install, either via my Magix Account or my order confirmation Email. It gets so far and the stops and displays Account Already Exists and goes no further.
You are seeing this error because the previous install has not been uninstalled fully, there are files and folders left behind, the uninstaller knows nothing about these as they are created on first run, which must be removed before re-installing - see this Support article.