You must run a firewall. In many new operating systems(eg. Windows XP), there is a built-in firewall. Google search on how to activate it. Others may try one at http://www.download.com

You may have a question by now. What is purpose of these spyware? Even though we cannot give an explicit and clear cut answer, we can safely state that everything boils down to urge of more profits. How? The spyware collects all your personal information and transfers it to an external computer. The information is reviewed by a software in receiving computer and then delivered targeted popup ads to infected PC. There are many things that spyware does in addition to this.

If you have some technical knowledge about your PC, here's a technical explanation on what trouble does spyware cause.

1. An extra process is running to monitor and log your activities. 2. Constant transfer is taking place between your PC and spyware server. (This is a two-way transfer)

Firstly, extra process in itself is an undesired process and it contributes to slow down your PC. Second point is most harmful. It transfers logged info on infected PC to external PC (Spyware server) and then external PC transfers targeted popups to infected PC. (Targeted popups are popup ads that are delivered based on user interests. User interests are analyzed by special software running on spyware server, using information transferred by your PC as input.) Since many extra processes are running (eg: monitoring processes, transferring processes etc.), your RAM (memory) will be shared and as a result, your PC will run slower. This also slows down your Internet connection speed because a lot of transfer is taking place and your total available bandwidth is shared.

In short, PC with spyware is like a dumping ground for snakes. Once its there up and running, it can do almost anything with your PC.

* NOTE: A useful tip - When you clean up your PC and close door for those harmful programs with a firewall, you can block many popups. But still, there can be some popups. There are popups integrated to websites you visit, and we must to do something about them. There are many popup blockers available on net, but I highly recommend installing Google toolbar, which has a quality pop-up blocker integrated to it. It also has some other useful features and is highly customizable. Download it free at http://toolbar.google.com.

The most risk is for people who use Internet Explorer, as it is most popular web browser and that very fact has drawn more attention of many malicious software developers. All of us want to make our PCs good and clean, right? So advise your friends about this, or if you had this article by email, just forward it.

Happy surfing...