HI,
I have just updated from 4.8 free to 5 AIS (for which I paid for). I initially installed 5.0.462. I got the "blue screen" during the install process, but the machine rebooted fine. Avast would load, but the services and shields would not start. I tried uninstalling and reinstalling and still I got the "UNSECURED" indication. When I click on the Fix button, the cursor hourglass flashes a few times, but the shields do not start.
I downloaded the 5.0.504 beta version and installed over the top of 5.0.462 and still have the Unsecured message, including the "X" through the Avast icon on the system tray.
I an running a fully updated version of XP Pro SP3.
Any good ideas from here?