Sometimes I connect DSL Modem windows says limited or no connectivity

Hi, I have a TP-Link single port DSL Modem witch connects RJ Lan port. i tried many times but windows says ur connections is limited or no connectivity and shows a yellow mark on connections on start bar. i want to know what is the actuall reason for that i changed IP manually and dynamically i tried many times but same.

then I tried to reset the modem but it stops. And when i type IPCONFIG at Command prompt it shows 0.0.0.0 address

can someone explain that.

Thanks to All.