Router assigns IP address to the computer but no Internet connection

I have always heard that a computer can only access the Internet through wireless only if the router assigns the IP address to the computer. I have an internet connection which is connected to my desktop computer which is running on Windows XP and is provided by Dlink wireless router. I want to share the same internet connection on my laptop which has Windows 7 on it. Whenever I try to connect the laptop to internet, the router assigns IP address to the laptop but no Internet connection. I cannot visit any websites from the laptop even when the laptop is connected to the router. As I am not much of a networking person, I need your help in solving the issue.

The router must be configured properly in order to share the connection between two computers. If the router is not configured properly then the computer which is connected to the router using Wifi will not be able to use all the resources of the network. I think the same is happening in your case, you are able to connect to the router but you are not able to use Internet on the laptop. Hence contact your ISP and get the correct configuration of the router from them. Configure the router according to the configuration provided and then check if you are able to access internet on the router or not.

I dont think it is because of the configuration of the router, as the computer is getting the IP address assigned to it. I would like to suggest you to check the drivers for network adapters if they are installed and working properly on the computer. Driver acts as a mediator between the operating system and the device if the appropriate drivers for the device are not installed then the device will not work properly. Go to device manager and check if there are any caution sign against the network adapter. Follow the troubleshooting procedure if there are any caution signs. After troubleshooting, try and update the drivers for the network adapter.

The router is not able to handle the wireless traffic and hence you are not able to access the internet on the laptop. All the routers work on the software known as Algorithm. Like any other software, algorithm of the router can also get corrupt. If the algorithm of the router gets corrupt then the router will not work properly. To solve this problem you will have to upgrade the firmware of the router. To upgrade the firmware of the router, connect the router to the computer using console cable. Open the official website of the manufacturer of the router and download the latest firmware which is supported by the model of the router which you are using. Install the firmware on the router. Remember to save the configuration of the router, as after updating the firmware, you will have to configure the router again. Once the updating procedure is done, configure the router and then reboot it. Try to connect the laptop to the router and see whether it gets connected or not.

DHCP running on the router is responsible for assigning IP addresses to the devices which are connected to the router using wireless connection. DHCP assigns the IP address to the device connected using Wifi from the pool of IP addresses. If the DHCP on the router is not working properly, then it may assign the same IP address to multiple devices which will lead to duplication of IP address on the network. If there are any duplicate IP addresses present on the network then the devices which are having duplicate IP address are disconnected form the network. Login to the router and disable the DHCP on it. Connect the computer to the router using a console cable as you can only access the router with disabled DHCP with a console cable. After sometime enable the DHCP again and save the settings. After rebooting the router, try and connect the laptop to the router. Hopefully it will connect.

The IP version on which Windows 7 works is IPv6 while the IP version of Windows XP is IPv4. If the computers running on Windows 7 and Windows XP are connected on the same network, then the computer running on Windows 7 operating system will not be able to use the network resources due to IP address mismatch. To connect the Windows 7 based computer to the network consisting of Windows Xp computer, you will have to turn off the IPv6 support of Windows 7. To turn off the IPv6 support of Windows 7, open the network connection wizard and then open the TCP/IP properties. In that, remove the check mark from the option "Use IPv6" and apply the settings. Now restart the computer and then try to connect it to the router.