limited or no connectivity Dell laptop

Yep that's a start.
More information would be good.

MY internet conncction says limited or no connectivity

i tries ipconfig /renew and it says DHCP server cannot be contacted

Service providers reported that the problem is with the laptop after verifying the connection with differnet laptop.

When i connect lan wire to my system, i see a orange light at the port...

What could be the prob with my laptop?
Do i need to install new drivers?

How to identify where exactly the prob is..?

I suspect the Router.

Try another laptop or pc. If they connect then the problem is on your PC else its the router.

Make sure your cable is working and that it is a Straight cable not a corss-over.
Take both points of the LAN cable and hold them side by side. The colors must be in the same sequence.

There should be a reset button at the back or bottom of it, reset it. Beware, that all your custom settings on it will be lost as set to default. If you haven't changed settings on it in the first place then go ahead.

Hope this helps :)
Grant