Still Cannot Uninstall 2021

I am running 2024 with 2023 still operational. When discovering that 2021 still seems to be installed, I have tried to uninstall it - through Windows, through Auslogics, through various methods son the forum, none of them get me past the point where t says that a previous version of 2021 is already (not 2023 or 2024!) and it cannot proceed further.

Suggestions?

I do need the disk space.

What happens if I just delete all of the files?