Nonetheless, Comodo program files/folders were created, but it couldn't be launched.
So I went ahead and uninstalled it. It seemed to go smoothly, so I then ran the setup again. But before setup finished, I received a dialog box letting me know that I successfully UNinstalled Comodo.
Apparently the uninstall hadn't yet finished before I started to reinstall. And the reinstall never successfully completed.
Again I have program files and folders, but can't launch the program.
Upon trying to uninstall once again using the remove tool from the control panel, I received a message saying that it couldn't be uninstalled (I forget the reason it gave). And now Comodo is not even on the list of programs that can be removed.
I tried reinstalling once again, but it won't, saying that Comodo already exists.
So, I can neither uninstall it nor reinstall it.