Having a hard time with your home wireless network? In this installment of Answer Line, Lincoln Spector tackles some of our readers' most pressing networking questions. Got your own tech puzzler for Lincoln? Send it to answer@pcworld.com.

Why Can't My PCs see each other on the network? They can all see the Internet.

--Chris Kwon, Dumont, New Jersey

Since all of your PCs can see the Internet, we can safely assume that you don't have a network hardware problem.

In Video: How to Find Other PCs on Your Network

Let's start our sleuthing with Windows' network troubleshooting wizard--not because it's likely to help, but because it's quick and easy. In XP, select Start, Help and Support. Click Fixing a problem and then Networking Problems. In Vista, select Start, Help and Support. In either version of Windows, click Troubleshooting, followed by Troubleshoot problems finding computers on a home network.

If that operation doesn't help (and it probably won't), check your firewall. Third-party PC firewalls like ZoneAlarm and Norton Internet Security often block local networks. As a safety precaution, begin by disconnecting your Internet connection, either by turning off your DSL or cable modem or by unplugging the cable that connects the modem to your router. Then turn off each PC's firewall.

If the computers still can't see each other, the culprit isn't a firewall.

If possible, turn on just one PC's firewall. Does the problem return? If so, check that PC's firewall settings and documentation to see how to make it local network-friendly. You may have to add your other PCs to a "Trusted Zone" or some such group.

Repeat this process with each computer. Don't reconnect to the Internet until all of your firewalls are back up and working.

Here are some more steps to take to troubleshoot other potential trouble spots.

Make sure that all of your PCs are in the same workgroup: Press Windows-R, type sysdm.cpl, and press Enter. (Alternatively, in XP click Start, Run, type sysdm.cpl, and press Enter; or in Vista click Start, type sysdm.cpl, and press Enter.) Click the Computer Name tab. If the workgroup name there doesn't match the workgroup name listed on your other computers, click Change.

Make sure sharing is on. Press Windows-R (or use the alternative method for XP or Vista mentioned parenthetically above), type ncpa.cpl, and press Enter. Right-click the appropriate network connection, and select Properties. If 'File and Printer Sharing for Microsoft Networks' isn't checked, check it.

If you're using Vista, you should also select Start, Network, and click Network and Sharing Center. There, you can fine-tune your sharing settings.

Make sure that you're sharing a folder: In XP's Windows Explorer, go to the folder you want to share. If the folder's icon doesn't have a little hand under it, right-click it and select Sharing and Security. In the resulting dialog box's Sharing tab, check Share this folder on the network, and complete the other options as you see fit.

If your operating system is Vista, the folder's icon should have a tiny picture of two people in the lower-left corner. If it doesn't, right-click it and select Share. In the resulting dialog box, type everyone into the text field, click Add, adjust the permission level (if you wish), and click Share.

If the computers still don't see each other, try a last-ditch stupid trick that shouldn't work but sometimes does: Press Windows-R, type the other PC's network path, and press Enter. The network path is probably two backslashes and the computer's name on the network, such as \\chris.

If this gambit succeeds, you can map the computer as a network drive or create a shortcut to it.