Wi-Fi Problems

Quick Checks

The first thing to check is that the wireless adapter in the computer is switched on. Usually the on / off mechanism is a hardware switch, sometimes it is a special key or key combination on the keyboard, and occasionally it is done entirely in software. The switch or key will usually show a ‘radio transmitter’ icon. Use the Device Manager to make sure that the network adaptor is not disabled. You could also use one of Nir Sofer’s networking utilities to see the state of the available wireless hotspots in the area (such as ‘WirelessNetView.exe’ or ‘WifiInfoView.exe’).

Enabling the Network Adapter

Control Panel ► Network and Internet ► Network and Sharing Centre ► Manage network connections ► Right-click relevant network adapter ► Click Enable.

Resetting the Network Adapter

Control Panel ► Network and Internet ► Network and Sharing Centre ► Manage network connections ► Right-click relevant network adapter ► Click Disable ► Click Enable.

Updating the Network Adapter Driver

From the Device Manager you can try using ‘Update Driver’, though this often comes back with a message saying that the latest available driver is already installed when it isn’t. If you look at the Web site run by the device manufacturer you can often find a more recent version of the driver. However, you might find that the latest version of the driver, which Microsoft seems unaware of, is not signed.

Checking that Supporting Services are Running

Make sure that the Windows Wireless Service is running (‘WirelessNetView.exe’ has an option to restart this service for you).

See that the ‘IP Helper’ service is disabled.

Make sure that the ‘WLAN AutoConfig’ (‘Wlansvc’) service is running, otherwise the system will not be able to enumerate WLAN adapters or manage WLAN connections and profiles. This will mean that even though the wireless network adaptor is working, and its driver is properly installed, Windows may report during automated network troubleshooting that ‘There might be a problem with the driver for the adapter. Windows couldn’t automatically bind the IP protocol stack to the network adapter.’

Trying Another Network

See if you can connect to another open network in the area, such as a BT hotspot for example (BT WiFi, BT WiFi with Fon, or BT Openzone), or an Internet café’s free Wi-Fi hotspot, just to see if the problem is solely with your home network. Note that you should never try connecting to a secure network unless you are properly authorised to do so, because it is illegal. If your computer cannot connect to any wireless network then the problem is with that computer, but if it can get onto other networks then the problem is with your router or broadband connection.

Checking for Offline Working

When a customer says that they cannot get onto the Internet with their favourite browser, first ask them to look at the ‘File’ menu to see if ‘Work Offline’ is ticked. If it is not ticked then the next step is to try using an alternative browser.

Checking for a Bad Router Connection to the Exchange

If the ADSL light is lit on your router, but not the Internet light, the router might be set up with the wrong user-name and password for connecting to the ISP.

The problem might not be the wireless connection to the router, but the router’s connection to the Internet. Use an Ethernet cable to create a temporary wired connection to the router, and if you still cannot get onto the Internet then sort out the broadband connection first. The wireless connection from the computer to the router might be alright, but it is of course possible that the broadband connection and the wireless connection are both broken.

Checking for the Wrong Encryption Mode

Check to see if the router is using WPA or WPA2 if the operating system running on the computer is only capable of using WEP. This is the case with Windows Vista SP2.

Power-cycling and Resetting

Try powering the router off and on again. If that doesn’t work then try resetting the router. However, always make sure that you know the broadband user-name and password before resetting. You can often retrieve the user-name and password by logging on to the router itself. Note that the broadband user-name and password are not the same as the SSID and wireless password used to connect to the router.

Checking for Interference

Check for possible interference from nearby devices such as baby monitors, bluetooth equipment, cordless telephones, and microwave ovens, for example.

MAC Address Filtering

Check the wireless router’s configuration to see if it is using MAC address filtering to keep out unwanted interlopers. If it is doing this then the MAC address of the wireless card will have to be somewhere in the ‘approved’ list.

MAC address filtering is a poor additional layer of security. A MAC address can be faked quite easily. A hacker could find out one of the MAC addresses in the ‘approved’ list just by monitoring wireless traffic, and then impersonate that address.

Most domestic wireless networks do not in practice use MAC address filtering because it is not a well-known feature and when guests want to use the Internet, the ‘approved’ list has to be updated. This is a lot more trouble than simply telling a guest the wireless password.

Making Sure that Power-saving is Switched Off

  1. Start the Device Manager (the easiest way is to run ‘devmgmt.msc’).
  2. Look under ‘Network adapters’.
  3. Right-click the wireless adapter of interest.
  4. Click ‘Properties’.
  5. Click the ‘Power Management’ tab.
  6. Make sure that ‘Allow the computer to turn off this device to save power’ is unticked.
  7. Click the ‘Advanced’ tab.
  8. Make sure that ‘Ad Hoc Power Management’ is set to ‘Disabled’.
  9. Make sure that ‘Transmit Power’ is set to ‘5. Highest’.

Finding Drivers for Unknown Devices

  1. Start the Device Manager (the easiest way is to run ‘devmgmt.msc’).
  2. Look under ‘Other devices’.
  3. Right-click the unknown device.
  4. Click ‘Properties’.
  5. Click the ‘Details’ tab.
  6. From the drop-down list select the property ‘Device Instance Id’ or ‘Device Path Id’.
  7. Look at the corresponding value which will look something like ‘HDAUDIO\FUNC_02&VEN_14F1&DEV_5045&SUBSYS_1179FF31&REV_1001\4&F53DD5&0&0002’.
  8. The vendor identity is ‘14F1’ and the device identifier is ‘5045’ in the example above. You can type in this information at pcidatabase.com.

Scanning the Wireless Spectrum

A very good program for scanning the wireless spectrum is the ‘Home’ version of inSSIDer, which you can get free from http://www.metageek.net/products/inssider. This is one of the best programs available for determining which is the optimal frequency for your wireless router to use in order to avoid interference with other nearby routers. Note that inSSIDer relies on Microsoft’s ‘.NET’ framework.

Toshiba laptops come with various utility programs, often including the occasionally useful ‘Connectivity Doctor’ (‘cfmain.exe’), which has a RADAR-like facility for displaying nearby wireless networks. The information displayed includes network names, locations, the channels that they are using, and whether or not they are secured.

There are many other utilities for viewing nearby wireless networks, including the plain but excellent ones written by Nir Sofer. However, most of them do not attempt to map the networks geographically. Having said that, the Toshiba utility is not that accurate, and even after allowing it to settle down for a while, wireless network access points do have a tendency to jump suddenly from one place to another.

Nir Sofer’s utilities include ‘WirelessNetView.exe’, ‘WifiInfoView.exe’, and ‘WirelessKeyView.exe’.

Wi-Fi Range Extenders

If you find it impossible to connect to your router wirelessly from particular places within your premises, you can probably solve the problem with a Wi-Fi range extender. These devices act as ‘repeaters’ to extend the Wi-Fi signal much further than it could normally reach. A popular model is the Netgear Universal Wi-Fi Range Extender WN3000RP.

Always Connect to the Right SSID

After installing a Wi-Fi range extender, you must make the usually-out-of-range clients connect to the extender’s SSID rather than the router’s SSID. It is possible that a computer will continue trying to connect to the router’s SSID, because the extender was probably only purchased after initial attempts to connect to the router failed or the connection proved marginal. Therefore any computer that knows about the router’s SSID should be told to forget about the router forever. The extender’s SSID is usually the same as the router’s SSID, but with ‘_EXT’ added on the end.

Using an Extender is Always Slower than Using a Direct Connection

Once a Wi-Fi range extender is installed, only clients that cannot connect reliably to the router should use the extender instead. This is because a connection to the router via the extender will always be slower than a direct connection to the router.

Configuring a Netgear Extender

You can connect a computer directly to a Netgear WN3000RP extender using an Ethernet port. It’s then possible to log in to the extender at http://www.mywifiext.net and configure it. The default user name is ‘admin’ and the default password is ‘password’.


Linux Wi-Fi Not Working

  1. sudo service network-manager stop
  2. sudo service network-manager start

…OR…

  1. sudo service network-manager restart