To solve the problem, first change your SSID's name, and then hide it. That way, passersby won't see it, and they won't be able to guess it either. How you do this varies from manufacturer to manufacturer, and even from model to model from the same manufacturer. But for many models of Linksys routers, including the WRT54GX4, here's what to do.

1. Log in to the setup screen, then click the Wireless tab and look for the Wireless Network Name (SSID) box. Enter the new name of your network.

2. On the same screen, look for the Wireless SSID Broadcast setting, and choose Disable. Then, click Save Settings.

3. If you are doing this from a wireless PC, you will immediately lose your connection to your network. So will every other wireless PC on your network. After you change your network name, reconnect each Wi-Fi computer to the network, using the new network name. You're now set.

Use encryption

If you take only one step to protect your home or small office network, it should be this: Use encryption. Wi-Fi networks are incredibly convenient—and incredibly easy to spy upon. All that data going out over the air among your PCs and between your PCs and the Internet can easily be snooped on by anyone nearby using simple, off-the-shelf software such as packet sniffers.

There are two encryption Wi-Fi standards --- Wireless Equivalent Protocol (WEP) and Wi-Fi Protected Access (WPA). Don't use WEP—it's not nearly as safe as WPA. In fact, the biggest security breach in history was caused because a store owned by TJX Companies Inc. that used WEP, which allowed hackers to break in to the network.

Here are the steps for the Linksys WRT54GX4 and many other Linksys models:

1. Go to the Setup screen and choose Wireless --> Wireless Security. In the Security Mode drop-down box, choose WPA/WPA2 Personal, then choose either WPA Personal or WPA2 Personal.WPA2 is a more secure method, but your hardware and software may not support it. Check your network adapter manufacturer's Web site to see if it supports WPA2 Personal. Windows Vista supports WPA2 Personal, but not all versions of Windows XP do.

To see if your version of XP supports WPA2 Personal, select Control Panel --> Add or Remove Programs. If the Show Updates check box is not selected, check it. Scroll to the Windows XP - Software Updates section and look for Windows XP Hot fix KB893357. If it's not there, your version of Windows XP won't support WPA2 Personal. You can, however, go to the Microsoft updates site, and download KB 893357 to turn on WPA2 functionality.