Real time Shields not running

Sorry if this query is already answered in another relevant thread. I apologise in advance for not sticking with proper forum protocol.

Just recently avast has stopped running all the real time shields but the firewall is still running okay. Every time I try to run the shields it fails. could anyone help me out here?

Thank you.

Repair avast!:

  1. Control Panel → Add/Remove programs → avast!
  2. Click on ‘Repair’.
  3. Follow instructions.
  4. Reboot.