Has your computer ever become so slow that you can fix yourself a snack in the time it takes your word processor to open? Spyware may be to blame.

Spyware has been known to masquerade as a prize-notification pop-up window.

Spyware is a category of computer programs that attach themselves to your operating system in nefarious ways. They can suck the life out of your computer's processing power. They are designed to track your Internet habits, nag you with unwanted sales offers or generate traffic for their host Web site. According to recent estimates, more than two-thirds of all personal computers are infected with some kind of spyware [ref]. But before you chuck your computer out the window and move to a desert island, you might want to read on. In this article we'll explain how spyware gets on your computer, what it does there and how to get rid of it.

Other "Ware" Malware - a general term for any program that makes changes (does malicious or "bad" things) without your express permission Adware - programs designed specifically to deliver unrequested advertising Stealware - specific spyware designed to capture clicks or Web-site referral credits Browser hijacker - a malicious program that becomes deeply embedded in your browser's code and core functionality

Some people mistake spyware for a computer virus. A computer virus is a piece of code designed to replicate itself as many times as possible, spreading from one host computer to any other computers connected to it. It usually has a payload that may damage your personal files or even your operating system.

Spyware, on the other hand, is generally not designed to damage your computer. Spyware is broadly defined as any program that gets into your computer without permission and hides in the background while it makes unwanted changes to your user experience. The damage it does is more a by-product of its main mission, which is to serve you targeted advertisements or make your browser display certain sites or search results.

At present, most spyware targets only the Windows operating system. Some of the more notorious spyware companies include Gator, Bonzi Buddy, 180 Solutions, DirectRevenue, Cydoor, CoolWebSearch, Xupiter, XXXDial and Euniverse.

Next, we'll look at the different ways that spyware can get onto computer.