Network lock turns itself off

Version 6.0.1203 windows xp

For some reason the network lock turns itself off at random times.
This started after recent program update.
Any ideas?

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. Uninstall avast from Control Panel (if possible). If, for any reason, you can’t run it, try booting in Safe Mode and doing it from there. Anyway, boot after that.
  4. Run the avast! Uninstall Utility saved on 1. If, for any reason, you can’t run it, try booting in Safe Mode and doing it from there. Anyway, boot after you’ve run it.
  5. Install avast! using the setup saved on 2. Boot.
  6. Register your free copy or add the license key for Pro. Or even upgrade your key from old versions.
  7. Check and post the results. If, for any reason, you did not solve, try doing the step 3 in Safe Mode anyway.