The DataStorage folder(and other folders) is created under OS environment variable TMP like below,
C:\Users\[OS user]\AppData\Local\Temp\TIBCO\Spotfire\12.0\DataStorage
Bot Web Player and Automation Services have configuration option to change it but Analyst doesn't.
Customer wants to change this location to driver D (or other location) for Analyst as well, to prevent it from fill up the C drive.