At this time BE does not support moving the data folder. While you may find some recommendations on how to achieve that end it is not supported option.
The best option is to stop all BE and SQL services, make a copy of the entire BE installation directory to a safe location, uninstall BE from the C: drive, reinstall BE to the D: drive reapply the same HF's to the new installation, stop all BE and SQL services, replace the new installation directory with the original BE directory.