In years past I have worked for both Microsoft and Intel Corporations.  When living in Japan for 5 years, I did consulting work for Canon and regularly helped in the big computer shows in Tokyo and Yokohama.  I am not officially a computer security expert, but you know, I have learned a few things over the years.  I have written programs in a variety of programming languages, which were then used in corporate micro, mini, and mainframe computers.
 

    PASSWORD PROTECTION

Let's say you're a hacker.  And you sure would like to have the banking and investment passwords of a hundred thousand Americans.  What kind of a program would you write?

"Password Protection!" - Hey, this is easy.  I'll call it, "Protect All" and give it away for free on the Internet.  Soon folks start to download and use it.  Great.  Let me thank you all in advance for giving me a copy of all your passwords!  Thank you!  I really do appreciate it.  Folks, stop for a moment.  Do you get it?  If you use one of these "free" password protection programs - how do you know that the programmer is not keeping his or her own copy of all your passwords?!

Use a piece of paper instead!

Your piece of paper won't be hacked.  And you maintain possession of all you passwords (not some hacker on the other side of the world).
 

    EMAILS & ADDRESSES & LETTERS & PHONE NUMBERS

Some of your most valuable information is small.  It's your personal stuff, like contact information.  Buy a few small USB flash (thumb) drives.  8GB or less is fine.  Small and cheap; get a 5-pack.  When your computer is on, just plug in the USB drive and make a full copy of all of your Emails, letters, and stored phone numbers onto it.

If you don't know how to do this let me make a suggestion.  Buy a few of the USB flash drives.  Then at your church or synagogue seek out one of those computer nerd guys.  You know the ones I'm talking about.  See if he is willing to do some consulting on the side.  What if you offered him or her $20 or $50 and dinner if he'd come over and show you how to do this.  (When he's there - write every step down.  And you do it!  He tells you on the side; you write it down as you're doing each step.)  This is a cheap investment!  Please don't delay, do this within the next month.  Once a month (as an example) you sit down and do the procedure that backs up your personal data onto a small USB flash (thumb) drive, then put it in a marked envelope in the desk drawer.  Next month use another USB drive and do it again.

If you have a small business you need more protection than just this.  But this article is aimed at individuals and common mistakes I've seen.  Backups are very inexpensive compared to trying to restore lost (or stolen) data later.

BACKUPS - they should be off-line, i.e. do not leave a backup external hard drive connected to your computer.  If you do, then a probing hacker can hit both the computer and it too!
 

    INTERNET CONNECTION - OFF WHEN NOT NEEDED

Buy a couple of extra surge protectors.  I would recommend 700 joules of protection or more.  Buy one for your computer and monitor, and one for your small internet modem, usually connected directly to your Internet service provider (ISP).  (For myself, I also use a UPS, an "uninterruptible power supply".)

I leave the Internet OFF most of the time.  Why have it on?  Your Internet connection is a gateway to the world.  This is both good and bad.  Let's say you have a big bay window on the front of your house, right at street level.  You can see out anytime you want.  But you know what, anyone walking or driving by can see in too.

Unplug your Internet connection (or use the on-off switch on the surge protector) when it is not needed.

And if you use a laptop put a small piece of tape over the camera too.  James Comey (former FBI Director) said that he does this.  And Mark Zuckerberg of Facebook does too.  So do I, and so should you.  Why have a camera pointed right at you all the time; it could be turned on remotely without you knowing it.  Just put a piece of tape over it when not needed.
 

    DOCTOR'S OFFICES

I am not basing this on any study, but I sure think that our doctors and dentists office networks may be the highest targets for international hackers.  Think about it.  Your whole family is listed with dates of birth, employment, all phone numbers, addresses for home and work, insurance, and maybe even your Social Security number.  What a treasure trove of information about you.

Doctors are not computer programmers.  That is on the side.  It is a part of the overhead.  "Okay, then go buy another printer or computer and connect it."  Let's get back to work.

For myself I pay an annual fee for "Identity Theft" insurance.  There are several vendors; I use Zander Insurance.  There are other good ones out there.  (Dave Ramsey recommends Zander, by the way.)
 

    ANTI-VIRUS

Probably the best free anti-virus software is from Microsoft.  It used to be called "Security Essentials."  But it is more recently called:  "Windows Defender"  It is pretty good and it is free.

But here is another idea.  Why use Windows?  When I worked at Microsoft many years ago, we were always being attacked.  Every week there was another serious threat.  I do not think that they ever successfully compromised our network - but they sure did try!  (And if it wasn't the computers, then they'd try to compromise the phone network.)

You, as a computer user, have a lot less visibility of what is happening even if you are under a direct computer assault.  You just know that your computer is running slower than it used to.  But you probably have no idea why.

Let's say you leave your Internet connection on all night.  Some hacker in China or Russia (or wherever) breaks into the modem.  He got in.  But he is stopped.  (Ahem, you DO turn your computer OFF at night, don't you!!?)  He can wait.  Hours later you get up and have a cup of coffee in hand.  You turn on your computer.  You look at some news and then go to an investment account.  Ah-ha!  That's what he's been waiting for.  He could (if successfully in your modem's operations) save a copy of every keystroke that you send.  Yes, I am sorry to say, this technology does exist.
 

    LINUX MINT

I have a few computers in my personal network.  Almost always my main Microsoft Windows machine is off-line.  I use a "KVM Switch" in order to use one monitor-keyboard-mouse, but multiple computers.

For over a decade I kept watching and trying out the various Linux systems.  They were getting better each year!  The most popular ones today are Linux Mint (and Linux Ubuntu) and a few others.  Visit "DistroWatch" and see the listings on the right side.  These are free to download and free to install.  You don't even need a new computer.  They are efficient operating systems.  Do you have an old WinXP or Windows 7 computer that you are not using anymore?  Why not download a copy of "Linux Mint" (or another one) and then use it (from a DVD or USB flash drive) to install onto the old computer.  Also install "Libre Office" after that.  See a few YouTube videos in order to do this.  Or pay a few bucks and dinner, and invite that computer nerd guy over for dinner again (if he/she is familiar with Linux).
 

    3 COMPUTERS

#1 - Linux Mint - for daily web browsing and Emails.  (In fact that is what I'm using to type up this article.)  With a good password this type of system is mostly immune from (all but the most determined) hackers.  The Internet (on a separate power switch) is OFF when not needed.

#2 - Linux Mint - for financial connections and updating my web pages.  Yes, a completely separate computer for doing financial (banking & investment) things.  This adds one more level of protection.  And of course, this computer is powered OFF almost all the time.  I turn it on only a few times per month.

#3 - Windows 7 (or 10) - For off-line (and usually non-English) typing.  I do a certain amount of things in other languages.  Windows (as Microsoft is global) is still much better for these types of things.  But I have the Internet (Ethernet; CAT-5) cable physically unplugged!  Too many computer viruses out there are written explicitly to attack known bugs in Windows and its main applications.  My Windows computer is off-line!

Usually, i.e. on a daily basis, only computer #1 (a Linux Mint system) is turned on and connected to the Internet when needed.  But when not needed, I go to the surge protectors and turn them all OFF.
 

    FINALLY

Get onto YouTube (or go to the library) and watch a few videos on "computer security".  In a few hours you will know more than 95% of the folks out there.

NEVER, EVER connect your main bank account to your Internet computer.  Never do this.  (Tomorrow - MOVE your money to a new account, if you have ever done this, even once.)  Either use a completely separate computer (that is left off, like I do) or go to a bank or credit union and open a new account, then put a few hundred dollars in there for PayPal, Walmart, Bestbuy, eBay, or Amazon purchases.  Folks, there are folks who have had their entire life savings stolen one night - while they left their computer and Internet access on - and a hacker was able to get in and get a few of the right passwords.  Stolen.  Gone.  All money never to return.  Do you like to eat watered-down soup every day?

Computers can be so helpful.  But they also open windows that go both ways.  You can see out, but others can sometimes also see in!  We need to protect ourselves.