Computer technology has advanced unbelievably quickly in the past decade. This has led to numerous solutions to ubiquitous problems in society, but at the same time it has introduced a lot of vulnerabilities to the computer systems that are used for these solutions.
While people generally associate the term computer hacker with bad guys, there are really two clear divisions within this term. The white hat computer hacker is a guy who simply wants to gain a deeper understanding of technology, and 'hacks' hardware or a computer program to do something it wasn't intended to - BUT it's important to note that they do not try to maliciously alter what they are hacking. The reason I make this distinction is because I currently work with a research group that involves people like this and they do not like the negative connotation of computer hackers.
Then there are the black hat guys. The guys that want to use their technological experience to compromise security of computer networks, steal someone's identity, spam your e-mail, make a profit off of innocent people, etc. These are the hackers that one needs to protect your computer from.
With this in mind, here are some simple steps to defend yourself from these bad guys.
1. The first step is to install antivirus and firewall software programs. I use the plural form because one single program does not usually work to stop everything. If you have multiple layers of software protection, there will be less of a chance that you install something you don't want. This type of software is best used for stopping internet viruses from being downloaded to your computer while you use the internet. Whether it's a virus, trojan, worm - you don't want it, because the possibilities of what this software can do is endless. It's really only limited by the imagination of the enemy.
2. Try not to store much sensitive or personal data on your computer, as this is what a lot of the bad computer hackers are looking for. If you do transfer this type of information over your connection, ensure you are using a safe channel, such as the https secure protocol, or some type of encryption, such as 3DES or AES.
3. Don't ever open files without scanning them antvirus software first. A lot of operating systems and web browsers have protection built in to do this for you, but it can't hurt to find additional software. The files you really need to look out for are executable files, or files with a .exe extension. Also, DO NOT click on links from an e-mail where you are unsure of the origin. This is known as spamming or phishing.
4. Use a firewall. Windows has a firewall built in, but many antivirus software programs have firewall protection built in as well. Essentially this is used to block incoming internet connections that may be a little shady. The antivirus software may only be able to scan files that are already on your computer.
You don't need to be a computer expert to protect yourself, but you do need a basic knowledge of the programs which will protect your computer for you. This is by no means an extensive list, but it should give you the basics to keep yourself protected from any unwanted outsiders.