If WiFi is not working

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Michael Pietroforte

Michael Pietroforte is the founder and editor in chief of 4sysops. He has more than 35 years of experience in IT management and system administration.

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As a digital nomad, I connect to a new WiFi network every couple of days. Thus, I think I have a good overview of the reliability of this wireless networking technology. It is not just that I constantly run into problems myself—I often see other people struggling with their Internet connection in coffee shops, airports, and hotels. My personal view is that all engineers who worked on this standard should consider moving to another field. Gardening, perhaps. Seriously, even the first acoustic couplers I used to connect to the Internet were more reliable.

Can't connect to this network

There are many reasons why WiFi is not working in a particular situation. In some cases, the WiFi router has crashed or is malfunctioning; in other cases, the client causes the trouble. In defense of WiFi router manufacturers, let me say that, in about half of the cases I discovered over the past five years or so, Windows was the culprit.

I used to believe that WiFi routers were just very unstable, because simply resetting the router often solved the problem. However, since I carry an Android device with me, I discovered that Windows has problems connecting to WiFi routers more frequently than do the various smartphones I had. Note that I also used different laptops, with different Windows versions and network adapters, and I always ran into the same problems. Thus, it appears to me that Android is more robust than Windows when it comes to wireless networking.

If your WiFi is not working, there are several things you can do. If you are an admin and a user calls because he can’t connect to the Internet in a public place, you can walk him through this guide here.

Open a web page

A typical beginner’s mistake is to connect to a public WiFi network and then launch an application such as an email client. Many public WiFi networks require you to open a web page first, either to show advertising or to have you accept the terms of service. Occasionally, you have to log on with a password. If Windows doesn’t automatically launch the default browser after you connect to the WiFi network, you have to manually open any web page. The WiFi router should then redirect your browser to the logon page.

Restart the WiFi router

I mentioned above that resetting the WiFi router often solves the problem. Unfortunately, this solution has some downsides. If you use WiFi in a public place, you often don’t have access to the router. If you are the admin of the router and other people are connected, you might be hesitant to restart the router because users might lose data if they are suddenly disconnected. In many cases, it is just one Windows machine that can’t connect to the WiFi router or the Internet. To ensure that the router is working, I try to connect with my phone. The Android device might connect in a snap, whereas Windows often says something like “Connecting to the network is taking longer than usual” followed by “Can’t connect to this network.”

Reset the WiFi adapter

The next thing I usually try is to reset the network adapter. This makes sense even if you can connect to other WiFi routers (your phone, for instance). Right-click the network icon in the systray, select Open Network and Sharing Center, and then select Change adapter settings. Right-click the WiFi adapter and select Disable. After the adapter is off, you can enable it again and see if you can now connect.

Reset the WiFI adapter

Restart Windows

If the above steps don’t work, restarting Windows might help. This applies even if you just turned your computer on. If you try to connect too early to a WiFi network when Windows is still in the boot process, the network adapter’s device driver or other components in the networking stack sometimes hiccup. So be patient before you connect again.

Disconnect WiFi

Computers are very stubborn fellows. If something doesn’t work, it usually doesn’t make sense to try it again. However, since WiFi is as unreliable as humans are, you can try to impress the router with your determination by making several connection attempts. Especially if the signal is weak, this often works. If you were connected to the router in the past and Windows tried to automatically connect when you booted up, it can help to disconnect and then connect again. Click the WiFi symbol in the systray, select the WiFi router you are connected to, and click disconnect. Then try your luck again and connect.

Disconnect WiFi

Forget this network

If your persistence didn’t convince the router, you can try expressing your disappointment with its performance by threatening that you are about to relinquish its services. This sometimes works wonders. One reason for having trouble connecting could be that you have connected to the router in the past but the owner has since changed the password (network security key). For some reason, Windows doesn’t inform you if reconnecting with a previously valid password fails. I think this is a bug. If you right-click the router and then navigate to Forget this network, the connection is reset. Windows will prompt for the new password when you reconnect.

Forget this network

Limited access

A very common WiFi error message beside the router icon in the Networks sidebar is “Limited access” or just “Limited.” This message appears in two different situations: either you are properly connected to the router but the router has no connection to the Internet, or you have a WiFi connection but the TCP/IP settings are incorrect. You can find out which problem you have by hovering over the WiFi symbol in the systray. If you see “Unidentified network,” something went wrong with your IP address settings.

Limited Access / Unidentified network

If you see the name of the router and “No Internet access,” the router is probably disconnected from the Internet and WiFi is not to blame. To verify that your WiFi connection is working, type ipconfig at a command prompt, look for the Wireless LAN adapter’s Default Gateway IP address, and type ping <IP address>. If the router replies, type ping 8.8.8.8. If you don’t get any replies now, the router is either disconnected from the Internet or the connection is just very slow.

Find gateway address with ipconfig

The latter topic is beyond the scope of this article and depends very much on the kind of Internet connection the router has (LAN, DSL, mobile, etc.). If Windows tells you that you are connected to an unidentified network, the real fun starts, and I will cover possible solutions in the remainder of this article.

Never trust error messages

There is one thing you should always do first: don’t trust the Windows “limited access” error message, especially if you connected and disconnected several times or if your WiFi connection is unstable. Windows sometimes gets confused. Open a web browser and see if your Internet connection really doesn’t work. If it does, don’t bother about the limited access. Windows occasionally detects its wrong assessment of your network status and sets the message back to “Internet access” after you have already downloaded gigs of data from the Internet.

If your browser can’t access the Internet, read on.

Unidentified network

In my experience, the “Unidentified network” error is the most common problem if WiFi is not working. This error usually means that the automatic assignment of the IP address settings through the router’s DHCP server has failed. The DHCP server might be down or malfunctioning. However, in many cases, the Windows DHCP client is the culprit. To check which is which, you can try a second device to see if automatic IP address assignment works. If other devices can connect to the DHCP server, you have a few options.

First, check if your WiFi adapter is configured correctly. Go to Network Connection in the Networking and Sharing Center (see instructions above), right-click the WiFi adapter, navigate to Properties, and verify that TCP/IPv4 is set to “Obtain an IP address automatically.” If that is the case, check what IP address has been assigned to your WiFi adapter. Open a command prompt and type ipconfig. Search for “Wireless LAN adapter WiFi:” in the output. If your IP address starts with 169, something went wrong. Automatic IP address assignment failed, and that is the reason for the unidentified network message.

Automatic IP address assignment failed

Optain IP address automatically

Troubleshooting DHCP

Next, you can try to convince the DHCP server to issue a new IP address. Type ipconfig /renew and wait until the command is completed. You might get a few error messages (“No operation can be performed…”) for network adapters that are disconnected. If the IP address of your WiFi adapter changed, you are probably done.

Get new IP address with ipconfig

If not, you could analyze the network traffic to see why DHCP is not working. My favorite network monitoring tool is the free Microsoft Network Monitor. To analyze the DHCP traffic, click New Capture, type protocol.DHCP in the filter field, and click Apply. Now click Start and run ipconfig /renew again. If the Windows DHCP client is working properly, you should see DHCP requests in Network Monitor’s Frame Summary window. If you don’t receive reply frames (check the Description column), the router’s DHCP server is probably malfunctioning or down.

DHCP server not working

DHCP server replies

Reset Winsock and the TCP/IP stack

If the DHCP server replies and you still can’t get an IP address, then Windows is the culprit. In this case, I would try to reset the Winsock entries with the command netsh winsock reset and/or reset the TCP/IP stack with netsh int ipv4 reset. Note that you have to run these commands from an elevated command prompt (with administrator privileges).

Reset network stack

Disabling and reenabling the WiFi adapter sometimes works (see above), and, of course, the most popular troubleshooting tip is always to restart Windows.

Disable all other network adapters

Sometimes conflicts with other network adapters in your computer prevent WiFi from working. Go to Networking Connections in the Network and Sharing Center and disable all network interfaces except for the WiFi adapter.

Set the IP address manually

If DHCP is still not working, you can try to set the IP address manually. Use a second device to find out the correct TCP/IP settings. On an Android phone, open the WiFi settings and then select Advanced. The IP address is at the end of the list. Choose another IP address in the same sub network (use an arbitrary number between 2 and 253 for the last position of the address). The subnet mask is 255.255.255.0 in most cases. As your default gateway, you can try either 1 or 254 for the last position of the address. Use Google’s public DNS server with the IP address 8.8.8.8 as the DNS server. Another option to find the correct IP settings for the WiFi router is to install the free ipconfig app for Android. Note that this can sometimes lead to IP address conflicts. If you get a corresponding error message, use another IP address.

Set IP address manually

If the “unidentified network” message is replaced with the name of the router, you are probably online. Believe it or not, this solved my problem in the majority of cases.

If this doesn’t work, there are still a few things you can try.

Change the security type

In some cases, I was able to connect to the WiFi router after I changed the security type from WPA to WPA2. This doesn’t necessarily mean that the router doesn’t support WPA2. It might just mean that a software bug prevented your Windows machine from authenticating properly. In one case, I changed the security type back to WPA2 and WiFi was still working. To change the security type, click the WiFi symbol in the systray, right-click the router, and then navigate to View connection properties. Now select WPA-Personal and try to connect again.

View connection properties / Change security type to WPA-Personal

Change (spoof) your MAC address

If everything fails but you know that the router is working because other devices have Internet access, the router might be blocking you. Perhaps you reached a time limit or downloaded too much data. Changing the MAC can also help to convince a malfunctioning DHCP server to issue an IP address.

Spoof MAC address

WiFi routers usually use the MAC address of your network adapter to identify your machine. You can easily fool the router by spoofing your MAC address. Some network adapters allow you to change the MAC address directly in the settings of the device driver. Right-click the WiFi adapter, select Properties, click Configure, and click the Advanced tab. Locate the network address and enter a random MAC address (for instance, 0206EAD72FEE). If your WiFi adapter doesn’t offer this option, you can change the MAC address in the registry. However, the easiest and fastest way to spoof a MAC address is by using the free Technitium MAC Address Changer tool.

Technitium MAC Address Changer

Install the latest WiFi device driver

If you are having constant problems with WiFi, it could be a problem with your WiFi device driver. Installing a newer version of the driver software, if one exists, might solve your problem. Right-click the symbol of your WiFi network adapter in the Device Manager (type “device …” in the Control Panel) and select Update Driver Software. Note that laptop vendors sometimes only offer the latest drivers through their website.

Update driver software

Tether your phone

If your phone can connect to the WiFi router, but Windows doesn’t, you can just use your phone to connect your PC to the Internet. All you have to do is tether your phone using a USB cable. If you didn’t bring a USB cable, you can also use Bluetooth. On an Android phone, you can find the tethering options in the Networking settings. Note that you can’t use WiFi tethering in this case because your phone only has one WiFi adapter, which you need for the connection to the router.

Android USB and Bluetooth tethering

Conclusion

I hope this little guide solved your WiFi problem. If you find this constant fight with WiFi too tiresome, you might consider working with mobile Internet in the future. I found that it is much more reliable than public WiFi; if you have LTE coverage at your location, your Internet connection will most likely be much faster than through WiFi. In my view, public WiFi will be dead soon. And this is good.