I know this sounds sad, but this is something Ive needed to know but still dont. I got the old laptop out and have just completed three full computer scans using three different programs(well it is very wet and windy outside). If they all claim to do a full computer scan then as far as im concerned the results should be the same,here is what I got. AVG scanned 214000+ files none infected time of scan 48 mins. Malwarebytes scanned 327000+files 7 infected time of scan 1hr 38 mins. Microsoft saftey scan 652000+ files none infected time of scan 1hr 54 mins. There seems quite a big difference in what they do, how do we know which is best and safest in this day of internet banking.