You're proud of yourself. You installed the latest and greatest antivirus software when you bought your last computer, and you've kept it current with the latest virus definitions. You have your operating system set to auto-update and install all the new security patches. You're careful about what you download and have your anti-virus program set to scan files before they're actually saved to your hard drive.

But suddenly your computer seems sluggish. It's slow to boot, and takes a long time to open or save files. You notice the home page in your browser has changed, but you don't remember changing it. You think you spot a new icon in the system tray, but can't remember if it was there or not. You suspect a virus, but run a scan of your entire system and it shows as clean.

What could be the problem?

Spyware!

Spyware can be installed on your computer without your knowledge, and can result in a number of computer performance issues. Spyware is designed to monitor or control your computer use. It can be used to monitor your web surfing, redirect your browser to particular websites, send pop-up ads, or record your keystrokes, which can ultimately lead to identity theft.

The key to protecting yourself from spyware is to learn how to recognize it, avoid it, and remove it from your computer. All computer users should take the time to implement prevention measures against spyware infection, educate themselves to recognize indicators that their system has been infected, and learn what actions are necessary to eradicate spyware from an infected machine.

Indicators of a spyware infection include:

- An unusually high number of pop-ups
- Your browser goes to sites different than where you tell it to go
- A new toolbar appears on your browser
- New icons appear on your desktop or on the system tray
- Keys suddenly don't work
- The appearance of seemingly random error messages
- Computer boots slower than usual
- Computer seems slow when saving files or starting programs

Fortunately there are steps you can take to drastically reduce your risk of a spyware infection. Those steps include:

Keep your operating system and web browser current. Spyware can exploit security holes in these programs. Software companies issue free "patches" to plug those holes as they're discovered. If there is an auto-update feature for your operating system and browser, make sure you have activated that feature to automatically check for and install those updates. It is also a good idea to check for updates manually, even when you have your system set to auto update.

Use both anti-spyware and anti-virus software, set up a firewall, and keep them current. Most anti-virus software doesn't detect spyware, and if it does it generally doesn't do nearly as good of a job as a standalone anti-spyware program. Make sure you have both types of programs installed on your computer, and that the programs check for and install updates daily.

Be cautious of free downloads. It's fun to download free games, screen savers, file-sharing applications, and toolbars. But it's also important to understand that some of these free software programs may also infect your system with spyware. If children share your computer, make sure you instruct them not to download programs without your permission.

Know exactly what you're installing before you install it. End-user license agreements (EULA) contain important information about programs and what they do. Be sure and read the EULA before installing any software, and if a particular program doesn't have a EULA, or it is hard to find, carefully consider whether you are comfortable risking infection of your system.

Minimize unapproved downloads. If the security settings on your browser are low, you leave yourself succeptible to receiving downloads that you aren't aware of. Ensure your browser security settings are high enough to detect these. Internet Explorer should be set to the "Medium" setting at a minimum.

Don't click on pop-up links. Click the red "X" icon to close pop-ups. Clicking anything within the pop-up window (such as a cancel button) might install spyware on your computer.

Install a firewall. A firewall will block outside access to your system and will alert you in the event spyware already installed on your computer is sending information to unauthorized users.

Back up your data. You have important information stored on your computer. Make a back up copy of everything you would like to have in the event your computer crashes. Do this often.

If you suspect your computer might be infected with spyware, immediately cease any activity that involves credit cards, bank accounts, user names, passwords, or other information that may compromise you personally. Check to ensure your security software is active with the most current updates, and scan your entire system for both spyware and viruses. Remove or quarantine anything detected as malicious.