Multiple Networks but the internet not connected!

Multiple Networks but the internet not connected! , my laptop running bye windows 7 home premium , i can browse but after 3minutes the internet will down . pls help me guys :""""(

You can be connected to multiple networks (Ethernet cable and WiFi for instance) and not have connection on either. It's still possible, keep in mind

Please check your Device Manager to see if your Network Adapters have any warning symbols beside them:

To do this follow these steps:

• 1) In the start menu type in "Device Manager" (without quotes) and hit enter
  2) In Device Manager expand the "Network Adapters" item, and look for any warning symbols beside each sub item

Try running the "troubleshoot problems" by right clicking on network icon in the notification tray (area). That will reset your adapter...and 9 times out of 10 will get things back again. If that doesn't work, try unplugging your modem/router from the power outlet for 1 min then plug it back in then reboot your system.