Web page not opening even though Wifi and Internet is connected

I faced some problem like this last week. I opened my laptop after 2 days. I went my home in Kolkata 2 weeks back, and after returning I didn't get time to spend some time with my lappy. Finally when I opened, I was unable to connect to the internet. In the system tray wifi icon was glowing and it shows computer is connected to Wifi network. But no webpage was opening. I tried different browsers. Nothing worked. I tried to ping some IPs and all the packets were lost. I tried to ping local IPs like 192.168.1.1 and same result was shown. This seemed to me unusual. Even if you don't have internet connection, you'll be able to ping this IP if you're connected to Wifi network.

Finally I tried IP Config and I was my local IP is 192.168.0.1. I was sure it's showing something which is unusual. I opened the TCP/IP connection properties of Wifi Internet connection. It was showing that the IP address is manually assigned to my system (the option was selected). I reset the option and changed to "Automatically Obtain IP" option and it started working.