MC 8.5.1 installer Error

Hi folks:

I keep getting an error trying to install 8.5.1.  It happens right at the end of the install.  Tried to run the uninstaller, and it says there's no software to uninstall.  Tried manual uninstall, then retried 8.5.1 installer, same eroor.

Any tips?  I seem to recall a detailed manual uninstall process on the boards here, but can't locate it.  Any help appreciated.

Best, JIM.