I still think you're joshing everyone, but well and oh well.
Start with the router, setup the firewall rules. AND DISABLE EXTERNAL LOGIN. That's in caps because it needs to be. If you can login to your router from anywhere in the world, someone can root it fom anywhere in the world. That's about the same as putting a sticker on your back that says "I keep my pistol here!" with an arrow pointing at where your CC holster is.
Then use the microsoft bareline security analyzer on each PC and make sure it passes completely....and keep it compliant. Follow the advice it gives as well. That will give you a computer that's pretty tough to crack.
Next, remove uneeded applications. Adobe products should be avoided unless required for a task. Acrobat in particular has been the means of intrusion for a few high profile examples this year. Some software just isn't made as secure as others.
From this point on, it gets harder...but you'll have higher and higher levels of security in return for your efforts. I highly advise getting some books that cover networking (I reccomend a Network+ study/exam guide) and get a Security+ study/exam guide. This is a far better alternative to me trying to fire off a cliff's notes version of around 2,000 pages of material.
Learning about networking will help you understand how it works. Knowing that a aemi-auto loads the next shot after it goes bang is one thing, but knowing that the ejector "flicks" the round away, the bottom of the breech face grabs the back of the cartridge as it's returning forward, pressing it into the feed ramp which guides it into the firing chamber is a whole other beast, and knowing that makes it easier to ID the source of a malfunction when it happens. The same applies to networking....the more you know, the more sense you can make of it all, especially when something goes awry.
Hardening is just the process of making sure your Computer/network is only as vulnerable as it has to be. It takes multiple layers of security to "bulletproof" a network.
