Why WiFi computer can't connect with wireless internet?

Sometimes the wireless strength in your local area may be too weak for your WiFi device to connect automatically to the Internet. In these cases, we suggest you manually connect to a named Internet connection by entering its network name (also called service set identifier or SSID).
 
If this still doesn't work, please check if the network password you entered is correct. If you have set your own WiFi password, please make sure your encryption method (WEP, WPA, or WPA2-PSK) is compatible with your router's model.