Hi Graham,
Please provide us with some further details. You can send your log files though here (http://download.avg.com/filedir/util/AVG_SysInfo.exe) and that will help us determine the issue.
why cant i install the renewal
I have been using AVG Antivirius Free for some years and decided to continue using it so that on the 17th November 2015 I sent GBP55.99 purchasing two years of your product. Since then I have been told by you that I must activate my license. I am to click on "Support" - which I have done and then click on "Reactivate" which does not exist - I could the enter my license number - which I cannot do.
Is there anything for me to do or am I O.K. doing nothing?