Sure. On Your PC do this...
1. Click Start - Run
2. Type in cmd click OK
3. A black command prompt window should open up. Type ipconfig/all just like that and press the Enter key
4. Make note of the DNS IP address. You can close the black window now
On while still on your PC open up a web browser page be it in Internet Explorer or whatever you use, it doesn't matter. Once you have that open do this...
1. Type in
http://192.168.0.1 press Enter just like you would to view a web page
2. You'll be asked for a username and password. It should be admin for username and leave the password field blank, click Ok
3. Now you should see a setup page with tabs going across the top of: Home, Advanced, Tools, Status and Help. Go to Home.
4. Once at Home you should see a tab called WAN to the left of the page click on that
5. Now you should see the two DNS fields. Enter the DNS IP address you got off of your PC to begin with
Now that should take care of it. If you still can't get the DNS on your 360 do this next...
1. On your 360 go to the System blade (purple one)
2. Select Network Settings and Press A
3. Select Edit Settings and Press A
4. Press A again and select manual
4. Enter a IP address, subnet mask, gateway and the DNS numbers. Use something like IP Address: 192.168.0.3, subnet mask will be: 255.255.255.0, gatway will be: 192.168.0.1, and then the DNS numbers you got of your PC again.
Now you should be up and running. Good luck!