Did you load Windows yourself?  If so, did you use the Dell recovery media or a copy of Windows from elsewhere?  What model system?

yes i did load Windows by myself  and i used Dell recovery media..

but even before doing that iv'e received that message..

system model : Inspiron 3537

yes i did load Windows by myself  and i used Dell recovery media..

but even before doing that iv'e received that message..

system model : Inspiron 3537

If you're connected wirelessly, check the router settings - sounds like you have a domain nameserver problem at the router level.

i'm connected wirelessly.. do you have any guide for setting the router correctly??