Thanks for the license. I did manage to get the non-free version of Avast working in the end. I forget how. I think maybe the license was just very slow in getting to me.
But now I have no Avast, neither the free version, nor the pay-for version.
I think probably AVG has killed off my Avasts.
How can I kill off AVG? I've asked AVG, but they have not replied.
I have in the last few minutes gone to Control Panel, Administration, Services, and STARTED two Avast Processes, which I assume had been stopped - I suspect by AVG. I don't know yet if my Avasts are now actually working again or not. I've not seen any sign of activity.