Laptop connecting to internet but no internet access (DNS server)

My laptop connects to the local network, but it has no internet access.
If I run troubleshooting it says that the DNS server isn't responding.
It is not the internets fault, because my room mate net works fine. It's not the cables fault because I tried plugging it in both of my routers and in both of my room mates, using his cable. And it doesn't work.
Wifi works fine elsewhere, but I don't have a wifi router in my dorm.
Things that I've tried:
Flushing my DNS
Adding custom DNS ports, like Googles or OpenDNS
Resetting the laptop to previous restore points
Using winsock reset
Disabling/enabling the network
Disabling Avast

I've changed nothing on my computer. The net worked fine on tuesday in my dorm. I went home and it worked fine there. Yesterday I came back to my dorm and it just stopped.

Try typing 74.125.21.102 in a browser window to see if you can reach Google. Check your roommates DSN settings and see if he is using the same DNS servers.