Avast Firewall Turned Off Warning

[REDACTED]

Hi
I've just upgraded to Avast Premier on 3 PCs. 2 laptops work ok (Windows 10) but on my desktop (Windows XP) I have an error message saying "Your Are At Risk, Firewall is turned off". There are 2 links, "Turn on" and "Resolve All" but neither of these do anything. When I go into Settings, Active Protection; it shows the Firewall as turned on and the same in Tools. So what's the problem here? Avast Support tell me I have to pay £120+ for a system check!!
Rob

[bob3160]

Try a repair of Avast:
Control Panel> Program and Features (Add/remove program)>Select Avast> Select Repair. Reboot when completed