How to Troubleshoot Your Home Network

Wi-Fi that crawls, connections that come unconnected, and printers that stop sharing — our expert provides remedies for these common network woes.

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.

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. 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, 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.

How do I share a printer over a network?
-- Irving Waldorf, San Francisco

I know of three ways to do this. Let's start with the free one:

You can easily attach the printer to one PC and share it with others at no extra cost. But there's a flaw: You can't print from any of the more distant computers unless the directly attached PC is left on.

If you're OK with that, follow the printer's documentation to install it on your chosen PC. Then, in Control Panel's Printers and Faxes applet, right-click the printer, select Sharing, confirm that Share this printer is checked and click OK to accept the default sharing settings for your printer.

On each of the other PCs, open Control Panel's "Printers and Faxes" applet and click Add a printer. In the resulting wizard, select the network option. It should find the printer and walk you through the rest of the setup.

If leaving the connected PC on all the time is a problem for you, consider buying a mini print server. Priced at $50 or less, a mini print server is a little box (often smaller than its own AC adapter) with a parallel or USB port at one end and Wi-Fi or Ethernet at the other. You plug it into the printer and the network, install a driver on all of your PCs, and everyone can print.

That's the theory, at least, and with a mini (or full-size) parallel print server, it's pretty much the reality. Any parallel print server should work with any parallel printer. For more about these handy devices, see Robert Strohmeyer's blog entry "Ease Small Office Growing Pains with a Mini Print Server."

Things aren't so simple with USB. If your printer lacks a parallel interface, you'll have to find a USB print server that supports your specific printer. You may have some luck searching on your favorite search engine for your printer model and the text string print server. Alternatively, you might check with the printer vendor and see which server it recommends.

Using a print server creates two other problems: It introduces yet another juice-wasting, always-on electronic device; and it leaves you with one more wall wart taking up surge-protector space.

If those problems turn you off, or if your printer lacks a parallel port and you can't find a compatible USB server, you can either accept the necessity of leaving the connected PC on at all times or turn to the most expensive option: buying a network-capable printer.

A printer that comes equipped with Ethernet or Wi-Fi is the simplest and most versatile solution, but the only way it makes sense economically is if you need a new printer, anyway. Just keep networking capabilities in mind the next time you go shopping for a new printer. Network-capable printers are available in all price ranges.

Why does my wireless speed vary so much, and why doesn't this variation seem to affect Internet performance?

-- Fritz Clayton, Las Vegas

If you've ever tried listening to the radio while your car was going through a long tunnel, you know that environmental variables affect wireless signal transmission. A family member turning on the microwave oven or a neighbor booting a Wi-Fi-equipped PC next door can degrade the Wi-Fi signal in your home.

And that interference -- if it doesn't kill the signal outright -- results in a slower connection. So it's not surprising that your Wi-Fi signal may be slower one day than another.

Why doesn't this reduction in data transfer speed appear to slow your Internet connection? The 802.11g Wi-Fi standard tops out at a transfer rate of 54 mbps. Even if interference cut the actual rate to a fifth of that speed, it would still be faster than almost all American household broadband connections. If you lived in Japan, where speeds of 60 mbps and higher are common, you probably would notice the difference -- and the lower transfer rate will certainly hamper the performance of such non-Internet network chores as transferring files from one PC to another. Hope for a strong Wi-Fi connection on the day when you want to transfer several gigabytes from one PC to another.

Or if hope isn't enough, see "25 Questions, 25 Answers" for tips on how to improve your Wi-Fi signal.

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