(I will ignore the 'separation of 'code' and 'data' design paradigm, which would rightfully require a third P: 'PROGRAM' drive, and I'll just focus on the lack-of-space problem.) The obvious intent was for all third-party (non-OS) programs to live on D: drive, or at least not on C: 'OS' drive. The D: drive is orders of magnitude larger. The C: drive has just enough room for Windows 10 plus some buffer for future 'OS' upgrades. Brand new high-performance gaming laptops, such as my ASUS Republic Of Gamers, come pre-installed with Windows 10 and two drives: A C: drive labeled 'OS' and a D: drive labeled 'DATA'.Reasons for installing to a non-default drive: The high-level question: When running the Android Studio installation program in Windows 10, and I tell it to install to D: drive (instead of the default C: drive), why does it insist on installing some components onto the C: drive? I'm going to start with the high-level 'common sense' question and then get into the tech details: