Tell me how to protect my computer

[BR7]

I use Trend Micro PC-cillin antivirus and firewall and it's worth every penny.I also use Ad-Aware and spyware blaster(both are freeware).When I used the free stuff I have to say zone alarm and Kerio were the best firewalls.And for free antivirus I would say AVG and Avast worked best

[Furiousg]

Zone Alarm just seems to have issues with certain PC's. I had used it exclusively on my first two pc's, and one at work...no problems. I put it on my last rig and it was fine. My mothers new machine had severe network problems and intermittent 60-70% cpu usage. She had a network guy at her isp tell her that he had multiple machines on that isp reporting similar problems. But it only happened on her new one. She is running Sygate now.

[Chokito]

I'm definitely not an expert (I can prove it by telling you that until yesterday I was running Norton LOL). My pc was like this . I still have a (small) BIOS problem, but the difference is incredible. Have to say, in total honesty, that I never got a virus while using it, but I also have to say that any software that can't be uninstalled without a special removal tool and a reboot is just not acceptable. I mean it's not like I married Norton!

Now for the debate:
I've been reading this and other posts about antivirus and security (need to replace the Norton with something) and what I think we need is a suggestion by someone that does use his/her pc for all those terrible things (p2p, xxx, hacker sites, ...). If I hardly ever surf, never download anything, etc, I probably don't need any special kind of protection other than the router's built in firewall. In the mean time I'll try AVG and ZoneAlarm.
Already installed Windows Defender. Is it any good?