I have tried Bit Denfender Free and it is not too bad; however, I dislike the fact that it is always running (eg, doing background scanning) in a never ending loop. Now their paid version uses a later technology (much like Avast Free) and there is no need to constantly scan for malware. In any event, if one does not mind the constant scanning and there is no worry about wear and tear on an SSD (if present), then Bit Defender Free seems to work OK. In summary, Avast Free still get my vote as the best all-around free AV solution!