ok now im going to budge in with my two cents:
i used to have the same issue, got a virus once messed up my pc, got another one , and another one:
got really sick and went to all the number 1 antivirus fora, hijack this and the likes, downloaded all the "best" antivirus, antispam and antimalware, rootkit protection, active firewall and browsing protection.tried everything, really to the point that i knew every feat of those programs.
still got notifications of, or viruses that got through.
controlling and checking the safety of my pc, would cost me at least three hours a week, mostly more.
my latest pc, very good machine, and up to date virus free, is without any protection, firewall turned off.
the only thing i use, is ccleaner, free proggy, most of you might know.
cleans up all the temp crap after browsing the net.
and ill tell you that that is your only time of danger: internet.
offline pc's dont have any prob, ever, unless you insert a floppy or cd with malicious software, but still mostly useless if you dont have internet, for the virus/trojan/backdoor to fulfill its function.
trust me, in most cases your ten times better off w/o any so called protection.
i am talking about your common user now, not about online business or proffessional websites.
just dont go to banner farms, porn sites or the cheats/hacks sites.
and dont use networking sites such as facebook, netlog and such.
and even on messenger, never click on any link unless your 100% sure your actually talking to your friend, never offline messages etc.
youll be fine 99% of the time.
after every browsing session use ccleaner, and youll have a ball with your pc.
if its about hacking: you cant stop it, unless your willing to invest all your freetime in learning how to, and the best always will crack you: the point is you dont have anything to offer for those elite ones.
only smalltime crooks, phishers, spammers and such are trying to get your info, lure you into clicking this or that.
only experience and attention can save you from this, no antivirus thats out there for free, can.
and even the ones you pay for are mostly outdated as soon as you install them.
take this info as you like it, im not saying its a fact, even if i believe it is
just my tip/opinion