Binho, você utilizou o Windows System Restore (Restauração do Windows)?
Sugiro que você faça uma instalação limpa do avast!
Você pode me seguir em inglês?
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 in
Safe Mode. Boot after you've run it. Repeat this for any major avast! version you have ever installed/upgraded in your computer.
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.