Kindly follow the below mentioned steps:
•Reseat network cable on the computer end and also from the modem/router end.
•Check if Link LEDs blinking at the computer end. If no response, Power cycle modem/router and try known good cable.
•If Link LEDs does blink or show response but no internet connection. Check IP address.
•If this issue started occurring after doing some recent software changes on your computer, then I would suggest you to restore your system back to a date when it was working fine. System Restore will affect Windows system files, programs, and registry settings only. For System Restore steps, you can refer to the URL mentioned: http://windows.microsoft.com/en-US/...
Share your comments if it solved your problem.
Thanks & Regards