Can't delete Avira?

I would like to delete Avira from 2012 or 2015 on a laptop, but this is displayed (picture) or if I want to delete the avira folder, it says something is being used in the folder.

And if I want to finish it properly, it won't show up there.

Go to the settings under Apps. You can simply uninstall Avira there. Simply deleting the folder does not help in 99% of cases, as you do not delete all files as files accumulate in several different folders.