Hello amonra and welcome to the forum.
This has nothing to do with your Virus Chest.
If you go to your Avast main page (GUI) > Real-Time Shields > Expert Settings > Actions > you should be able to see how you can change your settings here, then click OK/Apply on the bottom of the page (you may need to scroll down the page).
If you are missing parts of the page, then try an Avast Repair:
- Go to Control Panel > Add/Remove programs > Avast Antivirus.
- Scroll down and choose Repair function in the pop-up window.
- Reboot.
Let us know if this fixes the problem. Thank you.