I recently upgraded our 9.7 WS1 environment to 18.11.
The first attempt failed when the installer could not create the new services.
During the install process the installer gives this message:-
Clicking ok then gives you:-
At this point if you click ok the install will fail.
I went to services and checked the 6 services and found that SMS Agent Host and User Access Logging Service were still running, stopped them both manually and then clicked ok and the install completed correctly.
So key learning was to ‘slow down’ screen shot the messages and then check.