system
2
Right-click avast tray icon (“a-ball”); click On-Access Protection Control at top of menu. On the list at the left of the window that pops up, click the shield/provider you want to turn off; then click at the right of the window. A box will pop up asking whether you want to persist/save the changes; click .
http://i171.photobucket.com/albums/u319/tls_53/screenshots/on-accessscanner.jpg