Antispyware software is a necessity of the modern internet-connected world. Spyware is now considered the top threat to computer security, according to the Anti-Spyware Software Review 2007, surpassing even viruses. One of the reasons that spyware is such a threat is that many computer users are unaware that it even exists.

Unlike viruses, which are contained within program downloads, spyware files piggyback onto a variety of sources. Many websites will install a "cookie," this is a small file that tracks your usage of their website. These cookies are generally not malicious but do invade your privacy. They can be considered a form of spyware. Other spyware files are more dangerous, designed to track your overall internet behavior or even record keystrokes for purposes of stealing your passwords and/or gaining access to files on your system. This type of spyware is often attached to free software downloads or clickable popup ads.

In some cases, the line between spyware and adware becomes fuzzy and undistinguishable. Adware monitors your shopping patterns to create popup advertising that is customized to your needs. Strictly speaking, adware is not spyware since the focus is on creating advertising rather than tracking your movements. Then again, since the adware invades your privacy by noting your habits, it could be considered a non-malicious form of spyware similar to website cookies.

Unlike viruses, spyware files generally cause no noticeable damage to your system. Your computer's performance may be somewhat slowed or otherwise affected, but you will not notice a loss of data or system crash. This means that without appropriate antispyware software, spyware files may linger undetected for weeks, months or even years. Even if you happen to detect spyware on your own, uninstalling the files can be tricky. The piggyback nature of spyware makes the malicious file difficult to remove without uninstalling the wanted file to which it is attached.

Since spyware is difficult for the user to detect and remove, antispyware software is required. This will scan your system regularly for any spyware files and remove them. Most antispyware software can be set to remove adware as well.

Free antispyware software downloads are easy to find on the internet. You probably get offers for them everyday that are caught by the spam filter on your email. It is a good idea to do some research before you install any of these free offers on your computer, as they can actually be spyware programs in disguise. Always take the time to validate the effectiveness of any PC security software of computer firewalls that you are going to activate on your computer.

Whether you choose a free or purchased antispyware program, there a few things you should look for to determine whether the program will meet your needs. You want a program that will consistently monitor your system as an antivirus program does, blocking the majority of spyware from ever entering your system. The program should also give you the option of allowing or blocking suspected files, since no program can be 100% accurate in its determination of what is actually a spyware file.

The ability to customize the program is important, as is the ability to schedule full system scans at your own convenience. The program should be easy to install and use, and should offer regular updates. Finally, there should be a user's manual or website available in case you have questions about the program.

Spyware has become practically an epidemic in today's computer-addicted world. However, antispyware software, used in tandem with your computer firewalls and other PC security software, will assist you in safe internet usage. Understand the available features and select the program that works best for you.