Want to prevent people from using PSTs on your network?

You have Exchange for a reason, it stores your email, and you do diligence to back it up daily. The problem is those pesky users keep moving mail to their PSTs. Hard drives crash, laptops are lost and along with that, email.

Why not force your users to keep all of their mail on the Exchange Server?

Well, it's a simple Group Policy object for Office 2003 and Office 2007.The problem is, SBS 2003 doesn't allow you to send out Registry edits without building a template for it. Well, a company called DesktopStandard has you covered with their PolicyMaker - Registry Extension plug in to Group Policy! This program is free (with registration) and can be installed on your SBS 2003/SBS 2003 R2 box. And it's my understanding, this company is working closely with Microsoft to build it's tools.

Once you've got that handy program loaded, you'll have to work around a minor issue if you have IE7 installed. Make the following Registry Key change:
HKLM\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_OBJECT_CACHING
Create the REG_DWORD with the value of mmc.exe, and ensure the value is 0.

Once that's all finished, we're ready to create the registry keys. To do so, here are the steps:

1. Click Start, Administrative Tools, and click on Group Policy Management.


2. When the GPMC opens, right-click domain.local and click on Create and Link a GPO here...


3. Call the Policy something familiar to you, like Prevent PST Usage.


4. You'll now see what you just created in the list of GPOs, right-click it and choose Edit...


5. In the new gpedit MMC window that opens, under User Configuration, and User Settings, select the new node called Registry


6. In the right pane, right-click in some white-space and choose New, Registry Item.


7. On the new property page that opens, fill out the following:
   
   
   • Action: Create
   
   
   • Hive: HKEY_CURRENT_USER
   
   
   • SOFTWARE\Microsoft\Office\12.0\Outlook\PST\
   
   
   • Value name: PstDisableGrow
   
   
   • Value type: REG_DWORD
   
   
   • 00000001
   
   Similar to the following picture:
   


8. If you have any Office 2003 versions on your network, you'll want to also repeat the last step, but make the registry key for version "11.0" instead: SOFTWARE\Microsoft\Office\11.0\Outlook\PST\

You will not see the two registry keys in the "Report" of the policy, in fact, the policy will appear to be blank! The reason for this is the report only shows items that have an .ADM template file associated with them. Registry keys do not.

On the clients, this registry setting will take place once Group Policy refreshes, you can force this by typing gpupdate /force from a command prompt window. You will be able to see these registry settings applied to the client by running the command: Start, then Run, then type in RSOP.MSC and hit ENTER. This command gathers the resultant set of policy and shows it for the machine you are on presently.

There you have it! This policy prevents the PST files from growing (hence writing to PST files) It does not prevent the user from loading up any PST file and reading mail out of it.

Gotta love the power of Group Policy!