I am using ADSL2+ modem to access the internet in my HOME PC. As per manual instruction, I have configure my modem and access the NET . but some time interval my modem is get automatically out of configuration i.e. not provide internet service due to IP address is not found by my modem.
During configuration  my modem, sometime the network connection status show" limited or no connectivity...................." so that time i cannot connect modem to the service provider (ISP) too.
 so my question is:
(1) what may be probable cause to AUTOMATICALLY DISTURBED THE CONFIGURATION of my modem?
(2)Is there any  easy step to configure the modem and set network connection in desktop?
(3) How I solved the problem of "limited or no connectivity.........." in network connection status?
 please help me....
thanks
 souvikYour ISP (sometimes the Configuration reset at the Server Level) is responsible or probably your Modem have gone FAULTY!

You need to bring it to 'Factory Default' & configure again..

Here's How::

At the rear side of the Modem/Router, you'll see a Hole or a Button to reset it for Factory defaults, use a Pin or sharp object to press it persistently till all Lights of the Modem goes OFF!

Open http://192.168.1.1 in the address bar of the Browser.PUNCH in 'admin' at both 'Username' & 'Password' fields. Run the 'Smart Configuration Wizard' to ANSWER easy questions....& its done!

Revert for more inputs as per your observation.... thanks a lot........... same way i reset my modem in company setting........that a sharp thing used to hit the reset button. but it takes  not a single time..............some time it take four or more time...........and during the setting ,network connectivity status show"[b]limited or no connectivity[/b]".That time is  very difficult to connect to my  modem to ISP .....so what to do that time? how can i solved the " LIMITED OR NO CONNECTIVITY" problem?Assuming that you have correctly configured the Modem settings; Lets reach on to the TCP/IP Config. Screen!

Control Panel>>Netw Connections>>Right Click on the LAN Icon>>Properties?>>Highlight TCP/IP & press properties button

Chances are that these must be enabled to fetch IP Address & DNS Automatically!

Please choose the Manual setting against the both & punch in the relevant inputs