Before you can use D.N.S, please download install the latest version of Oracle VirtualBox for your main operating system
After you downloaded the .ova files from here, you need to import the file in your VirtualBox Manager:

Click on the button "Open Appliance...", select the previously downloaded D.N.S. .ova file and click on "Continue".
The next window lets you configure some details of the Virtual Machine. For example you can change the amount of RAM memory to assign to D.N.S. or add another CPU (by default only 1 CPU is assigned to D.N.S.).
If you are not sure about how to change these values, please keep everything as it is.
Before proceeding to click the "Import" button, please select the option "Reinitialize the MAC address of all network cards"

Next step is to agree to the license to use D.N.S.. You will need to accept the GNU GPLv.2 License.

The just wait that the import operation will finish.
