Imagine you want a contraceptive to prevent your partner to become pregnant. You get it, but you know you are not safe at all.
So you spend some more money to buy a better contraceptive. Still not safe.
Now you put much more money to buy the most-advanced-ever contraceptive.
Hurra!
You got a baby.
The perfect contraceptive was just to have an ugly partner and not having sex with her. 100% efficiency.
With OSs it's pretty much the same. You can install the best antivirus ever, you will waste your computer resources (and maybe money too) and someday you will get caught by a virus anyway. It's your destiny.
The perfect antivirus is an ugly operating system that nobody is interested to violate. Name? Linux.
Yep, Linux is pretty much hackable too, but who would care to spread a virus for the average John Doe's home-based Linux system?
The last time I formatted my computer was 8 years ago... the same exact time I have been running Linux.
Sorry for the creepy comparison... Just a morning reflection xD