I have a very small but very fast SSD as my "C" disk in my PC. I have a 2TB Dropbox account synched to a dropbox folder in my "D" disk, a 4TB internal Hard Disk.
I would like to do an automatic backup of my personal folders (Desktop, Pictures, Videos, Music, etc.) to Dropbox, buy I can not because my personal folders and the Dropbox folder are not in the same Hard Disk. I do not understand the reason for this restriction.