Unable to access the internet windows 7

Hello! I am running Windows 7 Home, and I am trying to connect to the internet on a school network. I have had no issues for the past year, then I booted up the computer and had router connectivity but no internet connectivity. I have no DNS information and a 169 IP address. When I try to go through the sequence flushdns, release, renew; I get a cannot connect to dhcp error. I have tried a lot of stuff, and would really like this thing to get working again.

PS: I replaced the NIC

thanks
Nick