I need to deactivate my Master Collection from one of my computers, however, the program never worked on that computer and was unistalled. How do I deactivate it? Even if I reinstall into that computer, the program won't open for me to deactivate.
I'm not sure. You may need to contact Adobe support.
Please note that the forum where you asked the question is devoted to the Adobe RoboHelp product and not all Adobe products generically. (you were asking about Master Collection)
You might try clicking the link below and seeing if any other forum comes closer to "Master Collection". I briefly looked at it and seems the closest I was able to come was "Creative Cloud". So maybe post there and see what folks have to say.