Windows Vista : Build Your Network (part 4) - Troubleshoot Wireless Networks

5. Troubleshoot Wireless Networks

WiFi tends to be temperamental, not to mention annoying and tear-your-hair-out frustrating. So, what do you do when you can't connect to a wireless network you've just set up?

Your instinct might be to attempt to connect again through the "Connect to a network" window. Or, if you're connecting to a network with a hidden SSID (described in the previous section), you may click the Set up a connection or network link to attempt to enter all the information about your network again. Of course, Vista will either let you complete setting up this network only to have it not work, or complain that a network by that name already exists. Arrgghhh.

Instead, you should go directly to the little-known Manage Wireless Networks window (Figure 10) via a tiny link by the same name on the left of the Network and Sharing Center window.

Figure 10. Use the Manage Wireless Networks window to fix broken wireless connections or delete wireless networks you no longer use

Here, you'll see all the wireless networks you've ever saved or set up manually, whether they're in range or not. Double-click a network in the list to show the Wireless Network Properties window (Figure 11).

Figure 11. Open the Properties window for a wireless network you've saved to change the connection options or modify the encryption passphrase/key

Here's how to solve some of the more common wireless connection problems:

Windows cannot connect to xxx.

This can be caused by a variety of problems, but Windows won't tell you which one. The most likely cause, at least when you're connecting to an encrypted network, is that you entered the wrong WPA passphrase or WEP key. If the network is hidden, you may have typed the wrong SSID (or if there's more than one hidden network in range, you may have selected the wrong one).

If you ask Windows to diagnose the problem, it'll probably suggest a weak signal, but that's unlikely if the network is showing up in your list with at least two signal-strength bars. More likely, it's not a real network (perhaps someone else's laptop errantly set to accept incoming connections), or it's using MAC address filtering.

Non-broadcasting network won't show up.

If you see an entry named Unnamed Network, select it, click Connect, and fill out the details of the hidden network. But if you've already set up this network and it still isn't showing up, then you've encountered a nasty little problem in Windows Vista.

Broadcasting (non-hidden) network won't show up.

If you're mixing old and new equipment, make sure none of it is set to work only with its own kind. For instance, many 802.11g routers have a setting that either permits them to talk to older 802.11b devices, or restricts them so only g-class devices can connect. If this is the case, make sure your router and all your devices are set to work with the widest range of standards.

Also, make sure both your router and your other equipment are communicating on the same channel (channel 6, 2.437 Ghz, is the typical default).

Windows tries to connect to the neighbor's network first.

Open the Manage Wireless Networks window and delete the entry for your neighbor's network if it's there. Next, double-click the entry for your own network to show the Properties window, turn on the Connect automatically when this network is in range option and turn off the Connect to a more preferred network if available option (unless it's grayed out). Click OK, and then drag your network to the top of the list (or use the Move up button just above the list).

After disconnecting, Windows immediately tries to reconnect.

Just click Disconnect again; Windows rarely does this more than two or three times. If the problem persists, open the Manage Wireless Networks window and delete the entry for this network.

A network called xxx already exists

You'll see this error if you try to set up a new wireless network with the same SSID as one already saved on your PC. If you've already used the Manually connect to a wireless network option to set up your network, don't go back to that if it doesn't connect. Instead, open the Manage Wireless Networks window and double-click the network to modify that entry's settings.

On the other hand, if you're setting up a new network that coincidentally has the same SSID as a different wireless network you've set up previously, see the next topic.

Handle two networks with the same SSID.

Windows distinguishes one network from another by its SSID; in other words, its name. Say you've named your home network wirelessnetwork, and you've got it working. Then, you take your PC to work and learn that the SSID there is also called wirelessnetwork. When Windows sees wirelessnetwork, it tries to connect with the encryption passphrase it already knows, and not surprisingly, fails.

The best solution to this problem is to rename your home network to something more unique, but this won't help if both networks are administrated by other people. In this case, you have to make some changes. First, open the Manage Wireless Networks window, right-click the network you have saved, and click Rename; this changes the name of the network entry while leaving the SSID intact. Next, double-click the saved network, turn off the Connect automatically when this network is in range option, and click OK. With that out of the way, you should be able to connect to the new network by the same name and save its encryption settings for next time.

If you frequently connect to different wireless networks, use the Network and Sharing Center  to quickly switch between Public and Private modes.

Windows loses its wireless connection when the phone rings.

If you're using a cordless telephone, it's likely the older 2.4 Ghz variety. 802.11b/g/n wireless networks operate on the same frequency, so move the cordless base station away from the router. For best results, replace your old phone with a new WiFi-friendly 5.8 Ghz model.

Windows connects, but the Internet doesn't work.

If you seem to be getting a solid wireless connection, but you can't load any web pages or check your email, open the Network and Sharing Center, shown in Figure 12. 

Figure 12. The Network and Sharing Center shows the status of your LAN connection, your Internet connection, and your sharing options, and provides links to most of Windows' networking tools

If it says Local and Internet on the Access line, then the problem is likely not with Windows, but rather with your Internet connection. Check your router status and restart your DSL/cable modem, if applicable. If you're on a public network, you might need to sign in or pay a subscription fee for full Internet services, a fact that might be clear from the first page your browser loads or perhaps suggested by the SSID. Of course, if other PCs on the network have Internet access, then try restarting your PC and temporarily disabling any firewall software that may be interfering.

But if you don't see Local and Internet here, but rather Local only or something similar, it means Windows wasn't able to get a valid IP address. This can happen if you're connected to an ad-hoc network (basically just another PC) instead of a true hotspot, but odds are that you need to mess around with your PC's TCP/IP settings .

Everything works until you enable encryption.

Open your router's configuration page and determine the current firmware version, which is usually shown on the home page or the Status page. Then, visit your router manufacturer's web site and see whether there's a newer firmware available; if so, download it and use your router's firmware upgrade feature to ensure you have the latest bugs and bug fixes. Likewise, make sure you're using the latest drivers for your wireless equipment on your PC.

If that doesn't help, it's likely that either your router or your wireless adapter in your PC is not fully 802.11i-compliant. This means you'll have to downgrade your encryption to one of the weaker standards explained in the "Choosing the Right Encryption Scheme: WEP, WPA, or WPA2?" sidebar.

Beyond SSIDs and encryption, a wireless connection is not much different than a wired connection.