Default location for PST files
Supported on: At least Windows Server 2008 R2 or Windows 7
Registry
HKCU
software\policies\microsoft\office\16.0\outlook Options
forcepstpath text Description
This policy setting allows you to specify a different folder location for Outlook Data File (PST) files on user computers. If you enable this policy setting, you can specify a location for PST files on user computers. If you disable or do not configure this policy setting, PST files are located in: %USERPROFILE%\Documents\Outlook Files\ on user computers.