Apply Your Knowledge

You want to ensure the computer you use to run the cafe is safe from viruses, spyware, and malicious code. Perform the following on your PC.

Remove Spyware
Spybot Search & Destroy has gained the reputation as one of the best standalone spyware detectors, monitors, and removers in the business. Spybot Search & Destroy is available free, although the Web site ( asks for a donation to defray development costs.


  • Download and install the latest version of Spybot ( ).
  • Run the application to scan for spyware, adware, hijackers, and other malicious software. Installation is simple and fast (although you should create a Restore Point with System Restore before doing so, in case you want to reverse the process).
  • Note how many references to spyware and adware the application finds.

Find Viruses
It is not actually necessary to purchase an anti-virus package if all you want to do is check your PC’s current virus situation. Increasingly, anti-virus vendors are offering scanning of your PC directly from their Web sites, a process that tends to take a bit longer than local scanning but which has four major benefits:

  1. You can successfully scan a PC that does not have the latest virus definition files installed locally.
  2. You are always assured of the most up-to-date virus scan possible.
  3. You can scan PCs on which, for whatever reason, you cannot install anti-virus software.
  4. You can get a second opinion to see if the results are different from those of your installed anti-virus program.


  • Go to Trend Micro’s Housecall, the online free virus scan corresponding to their PC-cillin product (
  • You need to agree to a download of an ActiveX control to have the virus-scanning software start; this is one of two apparent strikes against this method of virus checking. Since some of the fear surrounding spyware is precisely the vulnerability of your PC to software placed on your hard drives from outside, it seems counterintuitive from a security standpoint to allow an ActiveX control to install itself on your PC and then allow that control to scan all the files on your system.

Install a Personal Firewall
A firewall is a barrier to keep destructive forces away from your property. Its job is similar to a physical firewall that keeps a fire from spreading from one area to the next. A firewall is simply a program or hardware device that filters the information coming through the Internet connection into a computer. If an incoming packet of information is flagged by the filters, it is not allowed through.

Say that you work at a company with 500 employees. The company has hundreds of computers that are all connected. In addition, the company will have one or more connections to the Internet. Without a firewall, all of those hundreds of computers are directly accessible to anyone on the Internet. An outsider can probe those computers and try to make connections to them. If one employee makes a mistake and leaves a security hole, hackers can get to the machine and exploit the hole.

With a firewall in place, the landscape is much different. A company should place a firewall at every connection to the Internet. The firewall can implement security rules. For example, one of the security rules inside the company might be “out of the 500 computers inside this company, only one of them is permitted to receive public FTP traffic. Allow FTP connections only to that one computer and prevent them on all others.”

A company can set up rules like this for FTP servers, Web servers, Telnet servers, and the like. In addition, the company can control how employees connect to Web sites, whether files are allowed to leave the company over the network, and so on. A firewall gives a company tremendous control over how people use the network.


  • A variety of firewall software applications are available, including ZoneAlarm (, which is free for download. Microsoft has improved the firewall software in Windows XP and Vista, which is turned on by default. However, some computer manufacturers and network administrators might turn it off.
  • To open Windows XP or Vista firewall click on the Control Panel and click on Windows Firewall.
  • Download a firewall or setup the firewall included in Windows XP or Vista.

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