can't activate firewall

Since the last automatic avast update my firewall is not activated, when I try to actívate it a message comes up saying it is imposible. Any ideas what I need to do? Thanks

I suggest an installation from scratch:

  1. Download the latest version of avast! Uninstall Utility and save it.
  2. Download the latest avast! version and save it.
  3. (Optional) If you want, save your avast! settings for later restoration (Settings > Maintenance > Back up).
  4. Uninstall avast! from Control Panel (if possible) and reboot.
  5. Run the avast! Uninstall Utility saved on 1 in and follow the instructions. Reboot Windows in Safe Mode, uninstall avast! and then reboot in Normal Mode again.
  6. Install avast! using the setup saved on 2. Register your free copy or add the license key for the paid versions. Boot.
  7. Check and post the results.

Please, be patient, boot when it’s said to boot…