You said you only chose resident and web shield, so you already have it.
I would suggest the minimum is the Standard Shield, Network Shield (nothing to do with local networks), Internet Mail and thw Web Shield.
From Windows Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Change, click next and from the pop-up use the check the box opposite the options you want to enable. Once selected click Next and OK your way out.
