Roger,
You can find answer to your question together with your another post here https://support.avg.com/answers?id=906b0000000Dp14 .
Please try keep whole conversation in one question/thread to speed up resolution.
As suggested I have uninstalled AVG software and reinstalled it but the Mac software scan again did not complete, this time reaching >95% and finding 6 threats as before. So without completion I still do not have a means of identifying and remedying the threats. Is there a known problem with the Mac version of AVG?
Roger, In future please refrain from carrying out multiple topic postings on the same subject! You won't obtain an answer to your query any faster!.
AVG Guru