I do not have my Win 8 system in front of me so will do this from memory.
Open File Explorer by swiping in from the right edge of the screen, tapping Search (or if you're using a mouse, pointing to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Search), entering File Explorer in the search box, tapping or clicking Apps, and then tapping or clicking File Explorer. Before I clicked on File Explorer, I selected it and pinned to Task Bar. This makes it constantly available on the Windows Explorer App tile. Then I go to the Windows Explorer App tile, open the File Explorer from the Task Bar and can run anything from any file, anywhere, including CD/DVD.