Slow boot up

I find after reinstalling my OS the boot up was OK but after installing AVAST there was an incredible delay and also a blank screen presence before the desktop icons actually appear. I am not concluding but when I googled I got a few results on similiar lines and also a patch availability here.
Can anyone guide on this>>>(Settings → Troubleshooting → Enable avast! self-defense module). Am an average user so kindly make the answers discreet and without ambiguity…

do u mean u want screenshots on how to perform this instruction? (Settings → Troubleshooting → Enable avast! self-defense module).

here u go

edit: btw, is ur system locking up? if it is just delay bootup, u should 1st try checking “load avast! services only after loading other system services”
(u can see it in the screenshot too)