It is possible to create directory junctions in advance of the install and the installer will use them.
For example, if "Cakewalk Content" is currently installed at "D:\Cakewalk Content" open up a command shell as administrator and type:
mklink /j "C:\Cakewalk Content" "D:\Cakewalk Content" If you entered the command properly there should be an entry on the C: drive that looks like a shortcut and should open to the Cakewalk Content on D:
Now running the new BandLab Cakewalk installer will write Cakewalk Content to D:.