See my signature...
i would not install avast without file shield[U dont know about USB malware i suppose
and avast is awesome in detecting it without filesystem shield u wont be protected against it]
and web shield is another important component for web protection against exploits and ...
i recommend have avast installed with all shields irrespective of what u use...Apart from that u say about panda could AV that itself is a AV...two AVs conflicts u know
...kingsoft pc doctor=stay away from it!Never used it myself i dont recommend this....
Comodo firewall with Defence+ is a excellent combo with avast! pair it up with Malwarebytes pro..so:
Avast! free[all shields installed]+comodo firewall with defence+ +mbam pro[optional]+fully up to date windows =no malware!P.S. Mbam pro is optional for me as Comodo D+ is a solid warrior against malware If u want any help with Defence+ or something else in comodo Feel free to PM me....