Why is &quot;worse&quot; not OK but &quot;better&quot; is? Neither can be perfect and both will be far better than nothing. Just making up some numbers, but if the Windows AV can detect 80% of viruses and Norton can detect 90%, then you&#x27;re still vulnerable to that last 10% whatever you do. You&#x27;re also still protected from the majority of viruses whatever you do too.