I need help to install the MD83
Watch this, it will help.
https://flyawaysimulation.com/images/media/9183/how-to-install-full-aircraft-addons-in-fs2004/
If the question and answers provided above do not answer your specific question - why not ask a new question of your own? Our community and flight simulator experts will provided a dedicated and unique answer to your flight sim question. And, you don't even need to register to post your question!
Flight Sim Questions that are closely related to this...