Did any drivers come with that cable? I am trying to find more information on that cable, but keep hitting ad links.
Can you give us a quick configuration of your computer (similar to my signature)?
Before MC5 can see that input, the computer will need to recognize it. In Windows, if you hit the start button, type "sound" and choose "change sound card settings" you will see hardware your computer recognizes. If you do not see that cable listed, try unplugging and plugging it back in. I would think that some set of drivers was included with it, but looking for more info.
Edit: Here is a
thread from 4 years ago, and I share the same concerns of exactly what that cable is, etc. When recording into a computer, it is preferred to have an audio interface to stream signals in/out of the computer efficiently.