1.,8.7 installer broken and won't uninstall

[paulecrisp]

I have tried to install 1.8.7 on my Windows 10 PC today. It detected an earlier version and uninstalled it but then apparently quit. Windows reports that 1.8.7. is installed (but not a working version) but every time I try to install or uninstall it, I get a warning dialogue claiming that the app is running. The dialogue wont' go away except by killing it in Task Manager

I tried starting up in safe mode and running uninstall then but the same problem occurred

Any ideas how I get out of this trap?