Hi,
thank you for reporting it and trying the steps from
https://forum.avast.com/index.php?topic=212543.0.I would like to ask you a few additional questions.
Have you restarted the computer after the installation was finished or some time after that?
Also if you would be so kind and try to reinstall it once more with the latest Beta build from here:
http://tuneup.avast.tools.avcdn.net/tools/avast/betatuneup/avast_cleanup_setup.exe and then provide us with the setup log file.
Setup log could be find here:
c:\Users\<username>\AppData\Local\Temp\ we could find out why the reinstallation didn't work for you.
Cleanup setup log file name is something like this one:
Setup Log 2018-01-03 #001.txt.
The reason is that there is an additional logging implemented in the latest Beta build related specifically to the application service because this problem is most likely caused by the fact that the service could not be started for some reason.
Do you have a software on your computer which might somehow prevent our service from starting like a specific AV or something like that?
Thank you!