Yesterday I had more or less the same experience as titust11 above. My machine is a i5 9400F. After I activated in Uninstallr the removal of a handful of old programs, I came back from lunch and the Uninstallr was still busy with removal of the same program (Splashtop software) that I left with. And I was able to startup Taskmanager, but I could not select the screen. So I was not able to kill the proces. At the bottom right, all icons except for one had dispeared but I had to click fast and frequently, because the screens appeared and disappeared fast. Then I could select restart, but before that happened the check script of Uninstallr kicked in. After restart I got the message from Uninstallr that it was all succesful. BUT I am not quite sure about that. Nevertheless my system still works now, and the splashtop software IS disappeared from the menus, which is something I was not able to manage in the past years.
Still there is something wrong with Uninstallr. And it would be nice to hear something, what went wrong and if I have to be worried about my registry/system? Best regards Wijnand