Hello Justin,
From your question, I can understand that you are trying to install MATLAB in your desired folder path, but the downloaded files are still in the C drive.
Firstly, the below attached article can provide you with the correct way to change the temp directory the MATLAB installer uses.
How can I change the temp directory the MATLAB installer uses?
If the above doesn’t work, please contact Technical Support with a more detailed description of the issue you are encountering.
MathWorks Support information is available here: