system
6
Firstly, please be aware that this is genuinely a home system (not a business) - I run a windows server domain in order to provide added security for my family.
Also, I am aware that you are a volunteer and your help is much appreciated.
After following your instructions exactly and posting my results, I waited for your response as a courtesy to you, since I know how difficult online support can be when the person you are trying to help does ‘extra’ stuff… (I’ve been a programmer for over 40 years) 
Can I now safely apply updates to Avast and Windows XP? or is there something else I need to do to avoid this problem happening again?
Alex