I did a clean install of Ubuntu 22.04 and installed virtualbox 7.0 from a deb package. I later learned that installing from the virtualbox repository is a better Idea and removed virtualbox.
Next I added the repository and the pgp keys. However, when I try to install virtualbox I got the message "Running VMs found. VirtualBox is currently running. Please close it and try again. Please that it can take up to ten seconds for VirtualBox (in particular VBoxSVC daemon) to finish running."
Rebooting does not help. I am sure that I did apt remove --purge, no help. I next cleaned virtualbox from /usr/bin and /usr/share, I could not find any processes (e.g. VBocSVG) or services. with "find / -name <?virtual* and VBox*>" I traced any occurrent of virtualbox and erased it. When I try to install again "sudo apt install virtualbox-7.0" I get the message that virtualbox-7.0 is already the newest solution. Needless to say I can stil not find any trace of virtualbox.
In short: I messed my apt installation completely. Any suggestion to clean it up?