I ran Gibson Research's free ShieldsUp test for PC security. The test found some open ports on my PC. How do I close them?

Fu Weikai, Singapore

Steve Gibson's ShieldsUp service does an excellent job of testing your PC's security. Your computer uses the ports that the Gibson Research test probed to communicate over the Internet, but unscrupulous hackers can use the same ports to break into your computer.

Hackers use open ports--and sometimes even closed ones--to do mischief to your PC. But the scanners they rely on can't detect hidden (or "stealthed") ports.

A router with a built-in hardware firewall conceals ports: The router's ports, not your PC's, are visible on the Internet. Hardware firewalls cloak almost all of their ports by default, opening them only when necessary. (Software firewalls hide ports, too, but a router's firewall does an inherently better job. Of course, software firewalls are easier to update and reconfigure than routers, so if you have a broadband connection, it's safest to use both.)

Most routers close, rather than camouflage, port 113. Why do they do this? Once upon a time, some FTP, IRC, and SMTP servers used port 113 to verify where information was coming from. The port didn't have to be open, but it had to be visible to make the connection. If routers concealed that port, they'd block the network's access to a few outdated servers.

It's unlikely that a masked port 113 will ever cause you problems. On the other hand, a closed port 113 on a server is not a major security flaw...yet. Someday, a hacker may discover a flaw in port 113 in a popular router, and that could mean trouble. In the long run, you'll be better off hiding this port than closing it and leaving it visible.

Unfortunately, this port is not always easy to hide. The job requires that you reconfigure the router so that it will forward port 113 to a nonexistent IP address, such as "192.168.0.250." How you do this differs from one router to another, and the process isn't always obvious. On my D-Link router, for instance, the setting for forwarding ports is called "Virtual Server"--which is technically accurate but not really very helpful (see FIGURE 1). Check your router documentation and the vendor's online help for details.

'New' Message Gets Old

When I install a new program and click the Start button, Windows XP tells me that I have new programs installed, and the programs are highlighted for a time. How can I turn this feature off?

Andrew Steinberg, via the Internet

I've never needed this reminder, though I know people who like the highlighting because it makes new programs easier to find on a crowded Start menu. To remove it, right-click the Start button and select Properties, Start Menu, Customize, Advanced. Uncheck Highlight newly installed programs, and click OK twice.

Print Fonts and Save Paper

How can I save some trees by printing multiple font samples on one page in Windows?

Jeff Luckett, Bartlett, Tennessee

Use The Font Thing, a free program created by Sue Fisher. To print multiple samples, <Ctrl>-click fonts in the left panel, and then click the Print icon. Fonts need not be installed for you to examine and print them.

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