Problems with Google Chrome?

[steepbread823]

I was using google chrome when, my AVG protection pop up asking for it to be allowed access and instead of selecting allow I accidentally selected block and now every time I try to use google chrome this appears
"Add Google Chrome as a permitted programme in your firewall or anti virus software's settings. If it is already a permitted programme, try deleting it from the list of permitted programmes and adding it again."
I'm not very good with computers so a simple step by step instruction of how to resolve this would be very much appreciated.
Thank you