I don't remember, everything as its been a while but I added an SSD as the C drive and it has the system and programs on it but all my files photos and downloads go to my I drive. I believe I originally replaced my original drive with the larger drive, which is now my Data Drive. This system is Win 7 and older, I certainly could clean up a lot of remnants from the data drive but why take the time?
I also have a Win 10 laptop that I added a second SSD to with the same architecture;windows and programs on the C drive, files ,photos, etc , on the second drive.