Over the past few years, a new class of software has emerged that's up to no good. It goes by many names: spyware, adware, foistware, malware, eulaware, or even crapware. For simplicity we'll just call it all spyware. Here are some of the "features" you can expect from spyware. Some spyware may only use one or two of these tactics, while others do quite a bit more. * Reduced performance: This is probably the worst effect of these programs. Spyware uses up system resources, CPU time, memory, disk space, and Internet bandwidth, making your system noticeably slower than when it was new. * System instability: Most spyware is not properly tested or debugged, and there is no way to report bugs or obtain technical support. The result can be unexplained system crashes, (or "blue screens of death", as they're sometimes called...), screen freezes, or other strange behaviour. * Deceptive functionality: Spyware often uses a classic "trojan horse" tactic. It offers to synchronize your PC's clock or automatically fill in forms for you, but it is also doing some other nasty things while you browse. * Home page hijacking: Have you ever found that your home page has been changed, or discovered new sites in your "favorites" list that you didn't add? These were probably changed by spyware. * Loss of privacy: Many spyware programs keep track of the web sites you visit and send that information back to the spyware vendor. Even if you haven't done anything wrong, do you really want people you don't know or will never meet tracking your every movement online? *Unexpectedly high phone bills: Some spyware installs what are called "diallers", which quietly disconnect you from your Internet Service Provider's number and re-connect you to another number, usually at premium rates, perhaps on the far side of the world. * More advertising: Did you install a popup blocker but still find you're getting popups? The ads you're getting may not be from the web site you're on, but from spyware. * Stolen advertising: Instead of showing the ads that should appear on a web site, some spyware substitutes its own ads which can rob the legitimate site of revenue. * Broken web sites: Spyware sometimes changes the actual content on a web page, and in the process it "breaks" the page. The page may not look correct, or you may get Javascript errors. * Security risks: Some spyware has a built-in update feature that lets the maker download and install new code to your system any time they like, without your knowledge or prior approval. Why don't most antivirus utilities remove or block spyware? The short answer is "spyware is not a virus." Webopedia defines a virus as "A program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes." Spyware takes advantage of the fact that most people click "I Agree" to most software licenses without actually reading them fully. So technically, spyware is loaded with your knowledge and permission if you read the license, so it's not considered a virus. This devious use of software agreements puts the anti-virus companies in a tough situation. It's possible that you really did agree for some of this software to be on your system. If anti-virus utilities flag these borderline programs as viruses and remove them, the anti-virus companies could find themselves in a legal battle with spyware makers who claim they were given permission to install their software. Finding and getting rid of these cunningly-concealed "nasties" isn't easy, but with the experience I have in removing them, plus some very specialised software, your computer will soon be running much more smoothly and efficiently. In fact it will probably perform as it did when it was new, and before all this unwanted rubbish took up residence on your hard drive.