A few people have mentioned the DisablePST registry to me in the last couple of weeks, and wondered whether it had any effect on Enterprise Vault.

The short answer is no.

The DisablePST registry key is used to literally stop users using PST files.  They can’t open existing ones, and can’t create new ones.  It doesn’t affect programmatic access.  Here is a Microsoft article which talks about it.

http://support.microsoft.com/kb/896515/EN-US

eg 

HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook

DisablePST DWORD = 1

Remember the 11.0 should be swapped out depending on the version of Outlook.  I was using Outlook 2010 for this example, so I would be using 14.0 as part of the key.

Without it set, my Enterprise Vault client trace looks like this:

20/06/2012 10:11:34.044[2808][H]: [Offline Config] Working Directory: C:\Documents and Settings\jason1\Local Settings\Application Data\KVS\Enterprise Vault\82DFF9917466BB4881DC21D6BC6FDBF3\

20/06/2012 10:11:34.046[2808][L]: ~PVHelper::GetWorkingDirectory: 0x0
20/06/2012 10:11:34.046[2808][H]: DisablePST is not set in the registry
20/06/2012 10:11:34.048[2808][H]:
20/06/2012 10:11:34.048[2808][L]: PVHelper::IsRemoveOVSet: 0x0
20/06/2012 10:11:34.048[2808][L]: ~PVHelper::IsRemoveOVSet: 0x0

And, in Outlook I can see options for PST files:

View Inline Image

If I then implement the registry key and start Outlook again then the options for PSTs are gone:

View Inline Image

View Inline Image

The Outlook Add-in client trace shows:

24/06/2012 18:37:19.627[1972][L]: ~PVHelper::GetWorkingDirectory: 0x0
24/06/2012 18:37:19.627[1972][H]: DisablePST is set in the registry
24/06/2012 18:37:19.638[1972][H]: