When plugged into a USB port of a Windows XP machine, the BlackDog initially presented itself to the host as a virtual CD-ROM drive. Via an autorun application the BlackDog then automatically launched the X Window system for Windows Xming and a software NAT router. Once those applications were running, the virtual USB CD-ROM drive disconnected, and the USB presented itself as a virtual Ethernet adapter, enabling network access. Without requiring any installations or user interactions, the user could access the contained applications and data from any Windows computer. With further configuration steps, it was possible to also run the BlackDog on Linux and Mac computers.