How do I install iTunes on a non system drive?

This is a great guide to show how you can start using your D drive to store new iTunes for Windows content:

Change where your iTunes files are stored on PC - Apple Support

Since this only applies to new files you may wish to move your existing library over to that new location. This shows you where you can find your existing library:

Back up and restore your iTunes Library - Apple Support

See Make a split library portable - Apple Community. Although it is possible to use the non Microsoft Store installer to install the application on a different drive there is little benefit in doing so. It is the library that needs storing on a drive with enough room, and ideally in the portable shape so it can be easily backed up, restored, or moved again. Relocation iOS device backup data may also be useful, particularly on computers with relatively small system drives.

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