My home network setup consists of a router (D-Link DI-624S) which provides wireless network for two laptops (an LG with Windows XP and a Toshiba with Windows Vista) and also has an in-built print server allowing an HP Photosmart C6180 printer to be shared amongst all the computers. The wireless connection from the Toshiba laptop drops-out every few minutes when browsing the internet but seems OK when just checking email. Sometimes the connection restores automatically after a few seconds, but other times it must be repaired or requires a reboot. There is no communication problem when the Toshiba is connected to the router via cable and there are also no problems at all operating the LG over wireless. Following your previous advice for other questions I have used Task Manager to stop all non-essential processes to identify whether one of those processes was causing the problem. However, the problem continued when everything possible was switched off. The Toshiba computer is running Trend Micro for internet security. How can I fix this problem with wireless drop-outs?

You have already undertaken some good troubleshooting steps which will help us narrow down the cause of the problem. In particular, you have commented that the problem does not occur on the LG laptop computer. Therefore, we may assume that the problem is not with a faulty wireless router. However, we cannot necessarily rule out a configuration problem on the router and this is something which we may need to revisit later. Next, you mentioned that the problem does not occur when the Toshiba laptop is connected to the router via a cable, as opposed to wireless. This indicates that the general network configuration on the laptop is correct, although there could still be a problem with the wireless settings specifically. Additionally, the fact that you have tried closing all background processes, yet the problem continues, shows that it is not being caused by an awry process.

Before going any further, we need to narrow down the problem to either the laptop computer having problems operating wirelessly in general or there being a problem with your specific wireless setup (which would point towards something wrong with the wireless router). The best method to test this theory is to use your laptop on a different wireless network and see whether the problem continues. If you have a friend with a wireless network ask whether you can try your laptop on their network. Alternatively, quite a few clubs and restaurants offer free wireless which you could also use to test the theory. If you find that the problem does not continue when using a different wireless network there seems to be some incompatibility between the laptop and your home router. However, if the problem does persist on a different wireless network then the issue is related to the laptop itself. In either case, we will require more troubleshooting to find the root cause of the issue and work towards a resolution.

Dealing with the first situation whereby the problem does not continue on the different wireless network we need to take a look at the configuration of your home router and how your laptop is interfacing with the router. Looking at the Windows Vista Compatibility Centre the D-Link DI-624 series router is compatible with Vista so this should not be a problem. Therefore, the next step is checking the configuration on the router to determine whether anything could be interfering with the laptop. To be honest, I am unsure what configuration-wise could be causing this problem, particularly because no issue exists with your other laptop computer. Without the ability to check the settings and configuration myself the instruction which I can provide is limited. That said, there are two procedures which are usually undertaken when it seems that a router is causing problems. First, update the router with the latest firmware from the manufacturer’s website. The firmware is the software which runs on the router and is often updated by the manufacturer post-release of the hardware to add new functionality and fix identified problems. Visit the D-Link website (www.dlink.com.au/tech) and search for your router. I found there are two revisions of your router, so once you have determined the correct revision (instructions for finding the revision number are provided on the D-Link website) check whether any updated firmware is available for the router. You should be able to check the version of firmware currently running on the router by going to the router configuration webpage (usually accessible by typing something like 192.168.1.1 into a web browser on your computer) and then compare that version number to the version number of the firmware available for download.

If updating the firmware on your router does not fix the problem, or the router is already running the latest version of firmware, the next best option is to reset the router to factory defaults and then setup the router again from scratch. Before attempting this procedure make sure you write down all the current settings on your router so these can be reinstated, as the router will be in a factory-default state with no custom configuration. Once you have these settings handy, follow the instructions in the user manual for the router to reset to factory defaults and then commence setting-up the router again from scratch.

Dealing with the next possible situation where the problem does occur when using a different wireless network, indications are now pointing towards a problem with the computer itself. I consider this the more likely scenario particularly because you commented the connection drops-out when using the internet but not when using email. Additionally, when you use the term “drops-out” I am assuming this means the wireless connection is still established, but you cannot transmit data along the connection. In the past I have found the most likely cause of this issue is a problem with DNS. This is the Domain Name System which translates known domain names (e.g. Google.com) into their respective IP addresses (e.g. 74.125.67.100). If DNS stops working then you will find you can no longer access resources on the internet, much like the connection has dropped-out. Why this could be occurring on your laptop is unknown, but I have fixed the problem in the past by assigning computers a static IP address and DNS configuration rather than relying on these items being assigned by DHCP (an automated method to assign IP and DNS configuration settings). Therefore, assign a valid IP address together with the correct default gateway and DNS settings to the wireless adapter on your computer to check whether this resolves the problem.

In either case, whether this works or does not work, there is still further investigation to be conducted, more than can be explained in the limitation of this column. Therefore, please let me know what you discover through these investigations so we can work through the problem further if required.