My last question was about the level of scanning of the resident protection:
You can clicking the Resident Scanner button to set the sensitivity of avast! resident protection. There are three basic levels of the protection:
Disabled. The resident scanner is stopped. Not recommended.
Standard. Common, default setting. All executables are scanned when you run them and all documents and scripts when you open them. Only unread messages are tested in MS Outlook.
High. It is so-called paranoid mode - it works as the Standard mode but even files being copied are scanned. Additionally, all messages are tested on opening in MS Outlook.
If you set High, maybe you will get the most protection but with a lack of resources. See, you do not have to much RAM. Although avast is not a RAM eater, you can experiment some slowdown if you set it to High. Believe me, other antivirus will make it worse. I used McAfee, Norton and AVG...