Activating the program is different, depending on which version of the program you're using -- and you don't say which version of the program you're using.
The program allows for two activations of the program at a time. If you've already used one activation on your new defunct computer, you'll need to contact Adobe Tech Support, explain the situation and have them release one of your activations. (Note that this is a user-to-user forum, so we aren't able to do this. You'll need to contact Adobe Tech Support.)