Ive tried kasperspy, avast, and AVG free, i had AVG free for the longest and avast i thought the UI was horrid so uninstalled it after 5mins! now ive got NOD32 and its brilliant, everything i look for in an anti virus, great protection and doesnt hog the system, infact i dont know its running and updating automatically until i look on the updates section and it tells me! very impressed with it