Agree my initial query was as a result of CCleaner detecting what it considered to be a problem relating to dp Alexa. Looking at a broader perspective now in relation to input from others.
It seems that CCleaner perhaps detected a malicious file that Avast had not been able to delete but had put in quarantine. Could it even be a file rendered obsolete by Avast updates? Alternatively might probing of Avast by CCleaner caused reactions by Avast that CCleaner reported adversely?
Am I wrong to feel happier that dp Alexa seems to have been deleted completely from my system by CCleaner rather than being kept in quarantine? Malwarebytes now gives a clean bill of health?
Have heeded advice from computer magazines that Windows Defender should be de-activated because other AMATs are much more effective - guess some people are not aware of this.
This is the only apparent conflict I have had between AMATs and in this case I seem to have been better protected by not relying on just one product.