Error code: 0x8007232B - DNS name does not exist

i"ve received a message that my windows need to be activated.

i'm trying to activate my windows 8.1 in my dell laptop and i've received the following message:

Error code: 0x8007232B - DNS name does not exist.

i tried to load windows by myself using dell recovery media.. it didnt help either.

my system model: Inspiron 3537

how can i fix this problem??