Go to the official Xemu website. Get the version for your OS (Windows, Linux, Mac).
Many downloaded copies of Ninja Gaiden Black arrive as standard ISO dumps or extracted game folders. Standard ISOs will not boot on Xemu or modified Xbox consoles; they must be formatted into the XISO structure. Converting Extracted Folders to XISO ninja+gaiden+black+xiso+download+install
You can skip the conversion step entirely. Highly rated preservation repositories, such as Vimm's Lair, often host the game directly in the emulator-ready XISO format. Step 2: Converting a Standard ISO to XISO Go to the official Xemu website