My DNS address seem to be set to 18.104.22.168 (primary) and 22.214.171.124 (secondary). These are Google DNS addresses, right? How can I change this so that I get the DNS address from my ISP? I can't change this in Windows because the computer is connected to a D-Link router, and I can't find any option to change this in the router.
You need to go to your router settings, and modify it there. Your router's IP is likely 192.168.0.1
Once you get there, login using your d-link router's credentials, and then modify your DNS settings under the header "DNS." You may need to ask your ISP which DNS servers you should be using.