More than 75 percent of U.S. households now have Internet access. Along with the convenience of this powerful technology, we have the added responsibility of protecting ourselves from the proliferation of viruses and worms designed by hackers who are constantly trying to wreak havoc on our computers.

Let's look at these phenomena and what you can do to prevent them from harming your computer and network.

A virus is a file written by someone that attaches itself to a program on your computer (or even the operating system itself such as Windows).

Once it gets into your computer, the virus carries out commands such as displaying strange text on your screen, deleting files, etc. and it stays on your computer (unless it sends itself out as a file attachment) until you remove it.

A worm is a program with the primary objective of taking over your computer or bringing down your business network. Worms have received the most news coverage lately because of the problems they cause on such a large scale by targeting companies such as Microsoft and Sun Micro.

Both viruses and worms are very destructive and require effort to prevent them from infecting your computer.

First, you should always keep your critical data backed up. If a virus or worm attacks, you can always reinstall programs but a backup is the only way to recover your data. Second, install an antivirus program and keep it updated with the latest virus definitions.

Third, if you have a constant Internet connection such as DSL or cable modem, you must install a firewall to prevent hackers from finding your computer on the Internet and sending malicious code to your computer.

There are people out there with the intent of making your Internet experience miserable. To prevent them from having their way, either perform the defensive measures mentioned above or find a qualified consultant for assistance.

Michael Carter is the owner of Software Concepts, a Decatur-based computer consulting company that offers hardware and software sales and support.