Hi Cooljammer,
I am not from Laminar Research; just a flight simmer from down under.
Have you solved your problem?
Although I understand you want to run X-Plane on your "D" drive I remain confused on what has happened.
1. What version of X-Plane are you trying to run? Is it the true, genuine, original and official version created and developed by Laminar Research or the 3rd party modified hybrid version created by somebody else?
2. What is your operating system?
3. Why,have you, or did you, run the X-Plane installer file again?
4. Are you still in the "Installer" phase"? If so then attach your "X-Plane Installer log.txt" file
5. Alternatively if you are in the "full installation" phase then attach you "log.txt" file.
Both files are generated immediately after there is a system crash or you deliberately shut down. Details on how to attach the files can be found from the details provided by Greengolfer15 found in the following link at https://questions.x-plane.com/?qa=blob&qa_blobid=17830136656522860642
Glenn