well I've read all the presented solution here and on the ( how to ) and I still can't connect ..
I tried restarting the eth0
and a static IP address

I connect through a micro-tech server with a user name and pass , but I don't know where to enter them ..
there is another problem I think it may be related ..
on the Windows OS .. and using Google chrome
I have to uncheck (use a proxy server for your LAN ) every time I start the system and it get's checked back automatically several times in the same session and every time that happens the browser gives me (Server not found ) which is the same thing the Firefox gives me on bt4