I will be providing instructions for Windows XP and Windows 7.
Wi Fi A networks are 5 GHz, Wi Fi B networks are 2.4 GHz, Wi Fi G networks are 2.4 GHz, and Wi Fi N uses both 2.4 and 5 GHz bands.If so, then there might be a problem in your settings on the problem computer. It could be a lot of things, but interference and DNS problems are the most common in home networks.Are you connected to the network, but just not able to access the internet? One of the first steps in troubleshooting a network connection problem is figuring out if you have a valid IP address, and if it was configured automatically or manually.I can't tell you how many times I have gone to troubleshoot a network and they just have something unplugged, or didn't bother to reboot their router.(This is especially common with my parents...)The first thing you should do when troubleshooting your network is to take a step back and think about the facts you already know about the problem you are having.To see all of the information about your network adapter, go to command prompt and type ipconfig /all, and press enter. If it says no, it means that at some point a static IP address was configured, which may not be the correct IP address for this network.