Troubleshooting Windows 7 Wireless Networking Problems (Part 1)

If you would like to read the other parts in this series please go to

• Troubleshooting Windows 7 Wireless Networking Problems (Part 2)
• Troubleshooting Windows 7 Wireless Networking Problems (Part 3)
• Troubleshooting Windows 7 Wireless Networking Problems (Part 4)

Introduction

A few months ago, I purchased a new laptop to take along on what turned out to be an ill fated expedition to Antarctica (it’s a long story). Any time that I buy a new computer, the very first thing that I do is blank the hard drive. That way, I can get rid of all of the garbage that is preinstalled at the factory. Blanking the hard drive also ensures that I know exactly how the machine is configured. That way, I don’t end up running into any surprises later on.

In this case though, there was a surprise. After installing Windows 7 and loading all of the latest drivers, I began to notice that the computer had trouble maintaining network connectivity. A wired network connection worked flawlessly, but wireless connections were very unreliable.

When I would initially boot and then log into the laptop, the wireless network connection was completely functional. After a random amount of time though, I would be disconnected from the network. The disconnection sometimes occurred after only a few seconds of network connectivity, but other times I would remain connected for upward of ten minutes.

Technically, my laptop did not actually disconnect from the network. Windows continued to show that the laptop was connected to the network. However, an icon in the lower right corner of the screen indicated that the connection was limited. In other words, I remained connected to my wireless network, but once Windows reported limited connectivity I could not so much as ping my access point.

As I began to realize that none of the common Wi-Fi fixes were going to solve my problem I began looking around on the Internet to see if Windows 7 had any known problems with wireless networking. Although Microsoft does not acknowledge the issue in any of their knowledgebase articles, I discovered hundreds of different Web sites containing forum posts from people who were experiencing the same wireless networking problems that I was. Since the problems seem to be so wide spread, I decided to research the issue in hopes of helping others to fix any wireless networking issues that they may be having.

My Solution

As I researched the various Wi-Fi connectivity problems that Windows 7 users experience, it became obvious to me that there is no one single fix for the problem. There are several different issues that contribute to the Wi-Fi reliability issues, and any one of those issues can produce the symptoms that I described earlier. That being the case, I want to start out by telling you about how I fixed the Wi-Fi issues on my own network. I will then go on to discuss some of the other possible fixes for the problem.

Before I tell you what my fix was, I need to give you a little bit of background information regarding the way that my network is configured.

As many of you know, I work out of my home and have therefore converted the entire second floor of my house into a datacenter. Last year I spent a lot of time traveling to various IT conferences, and I took a couple of long vacations. Whenever I am going to be away, I have someone that I trust to come to my house twice a day to take care of my cats, and to do various things to create the illusion that I am at home so that hopefully no one will break into my house. Even so, I still tend to be a bit paranoid when it comes to securing my home.

Besides taking numerous other security precautions that I would prefer not to publicly disclose, I decided to invest in some security cameras. Ultimately, I decided to invest in IP based cameras. The idea was that I could tie the cameras into my wireless network. This would not only save me from having to run coaxial cable to the cameras, it also meant that I could use a dedicated Web site to monitor my home from anywhere in the world. Never mind that the cameras also had built in motion detection capabilities, and could be configured to send me an E-mail alert and a short video clip whenever motion was detected.

It seemed that I had found the perfect solution for remote surveillance. When the cameras arrived though, I had trouble connecting them to my wireless network. A phone call to the manufacturer confirmed what I had suspected. A bug in the camera’s firmware prevented it from being able to work with a WPA encrypted network.

Since I wasn’t willing to give up WPA encryption, and I had already spent so much money on all of the cameras, I decided to invest in another access point. I configured that access point to use WEP encryption, and connected all of my cameras to it. Since WEP encryption has well documented vulnerabilities, I chose to treat the access point as an isolated network segment. The access point that is used by my security cameras is not tied into my primary network, and the only computers on the segment are configured to record the streaming video from the cameras and to provide remote access to the cameras.

As I’m sure you have already figured out, my problem was caused by having multiple access points in close proximity. I have to admit that it took me a while to figure out the cause of the problem though. The reason why it took me so long was because only computers that were running Windows 7 were affected by the problem. I have several computers running Vista, and one computer running Windows XP, and these machines had no trouble with wireless connectivity. Likewise, none of my security cameras had any trouble connecting to the wireless network.

As I began to look more closely at the problem, I realized that Windows 7 wasn’t the only thing that was unique about the computer with the unstable wireless network connection. That computer was also the only one using 802.11n. As you probably know, 802.11n makes use of multiple data streams by using separate antennas.

Out of curiosity, I unplugged the access point that I was using for my security cameras, and my Windows 7 connectivity problems went away. Plugging the access point back in caused my Windows 7 machine’s network connection to fail within minutes. After repeating this test several times, consistently receiving the same results, it became apparent to me that my secondary access point was interfering with my ability to maintain a reliable network connection.

Conclusion

Once I figured out the cause of my connectivity problems, I began unplugging my secondary access point whenever I needed to use my laptop. Of course this was not a good long term solution. Eventually, the camera manufacturer released a firmware update that made it possible to put the cameras onto my primary network without having to disable WPA encryption.

Even though this particular problem was specific to my network, I wanted to go ahead and talk about it because I haven’t seen anyone else mention interference from another access point as a potential cause of connectivity failure. In Part 2, I will continue my discussion by showing you some settings within Windows 7 that can be used to solve some wireless connectivity problems.