A "wireless router" is a device that transmits Internet signals it receives from an Ethernet cable into your home or office, permitting computers in its vicinity to access the Internet wirelessly. In the case of wireless Internet, computers connect to routers and not to the Internet itself, so if a computer is connected to a wireless router but isn't connected to the Internet, the problem lies in the wireless router.
Connecting to Wi-Fi
The usual procedure of connecting to the wireless Internet involves locating your router's name in Windows' list of nearby wireless connections, then entering its password if it has one and connecting to it. If you enter the incorrect password or can't connect to the router, Windows gives you an error message and your wireless connection manager informs you that connections are available, but that you aren't currently connected. If you do connect to the router but Windows informs you that it has "no Internet" access, any several problems may be to blame.
One way to troubleshoot a faulty router is to simply reset the power. Just as a computer left on for too long can become slow and, in extreme cases, nonfunctional, so too can a long operation period render a wireless router useless. To reset your wireless adapter, unplug the AC adapter from its backside for at least 10 seconds, then replace it. Wait for all the lights on the front of your router to re-illuminate, then return to your computer to see if Internet access has been restored.
Ethernet Cable Issues
Another potential means of troubleshooting your Internet involves removing and then replacing the Ethernet cable, which looks like a wider version of a telephone cable. From time to time, a small gap may develop between the end of the Ethernet cable and the receptor inside the router, inhibiting necessary signal from flowing. To remedy this, remove the Ethernet cable for at least 10 seconds, then reinsert it into the router. If your computer successfully gains Internet access after you do this, you know the problem lied in the cable connection.
Router and Internet Service Problems
Alternatively, the problem could lie in the router itself. To test this, remove the Ethernet cable from your router and insert it directly into your computer's Ethernet port. If your computer connects to the Internet, your router is faulty. If it doesn't, the problem lies with your Internet service provider, or ISP. Contact the company you use for Internet service to regain connection to the Internet, or to figure out why there's a service interruption and how long you should anticipate waiting for it to be corrected.