Getting a new Windows computer this holiday season? Fresh out of the box it's vulnerable to viruses, scams and unwanted advertising. Before going online, lock down your computer by completing the following five steps in order:

1. Establish a firewall. Unless your new PC has been sitting in a warehouse for more than a year, it should have Microsoft Windows XP Service Pack 2. This update tightened the operating system's security.

One way it did this was by having Windows Firewall automatically enabled. To verify that the firewall is indeed working, click Start, Control Panel, Windows Firewall. Ensure that the circle next to "On" is checked. Also, check the "Don't allow exceptions" box. This blocks all requests to connect to your computer from other programs, but still allows you to connect to the Internet.

2. Update Windows. After you've ensured that Windows Firewall is enabled, it's time to update Windows. Microsoft periodically patches holes in Windows that could be accessed by hackers. The computer will need to be connected to the Internet to download the updates.

To update Windows, click Start, All Programs, Windows Update. This will open your Web browser and automatically take you to Windows Update's Web page. Once there, click "Express."

3. Prevent viruses. Most new computers come with anti-virus software preinstalled. Find and start the anti-virus program, then locate its update feature. These updates include definitions, which identify viruses. As new viruses are written, definitions must be updated.

Typically, anti-virus programs that come with new computers are only good for a short trial period. After that, the program will continue to run and monitor your system, but it will do so with old virus definitions. That's better than nothing, but not by much.

To continue receiving updates, you'll have to buy the full product — about $40 for a year's worth of updates. If you don't want to pay for continued service, AVG Anti-virus (http://free.grisoft.com/doc/1) and avast! (www.asw.cz/eng/free_virus_protectio.html) offer free products for personal use.

4. Stop the spies. Adware sits on your computer and feeds ads to you. Spyware collects information about you and reports back to a computer over the Internet.

Far worse are keyloggers, which record your keystrokes and e-mail them to crooks. They are used to steal passwords and credit card numbers.

A number of programs are effective against adware, spyware and keyloggers, including McAfee AntiSpyware (www.mcafee.com/us; $20) and Webroot Spy Sweeper (www.webroot.com; $30); and such free programs as Ad-Aware SE Personal (www.lavasoftusa.com), Spybot-Search & Destroy (www.safer-networking.org) and Microsoft AntiSpyware (www.microsoft.com).

5. Extra protection. Consider a stronger firewall. Windows Firewall does not have the features offered by OutpostFree (www.agnitum.com) and ZoneAlarm (www.zonelabs.com). Both are free.

You also might want to consider a security suite. McAfee, Panda Software (www.pandasoftware.com), Symantec (www.symantec.com) and Zone Labs offer anti-virus, anti-spyware and firewall capabilities in one package. Prices range from $40 to $80, depending on the version you choose.

Contact Kim Komando at gnstech@gns.gannett.com.