How to compact an Outlook PST file

After you remove messages or attachments from your mailbox, the PST file size will not necessarily reduce by itself. In order to shrink the size of the PST file, you need to compact it.

To compact a PST file:

  • Right click on the top-most folder of your PST. (It is usually called “Personal Folders”, but may also have a different name).
  • Select “Properties for…”
  • Click “Advanced”
  • Click “Compact Now”

See [permalink href=”14″]more tips on improving Outlook performance and stability[/permalink].

Workaround for “The connected state of Office Add-ins registered in HKEY_LOCAL_MACHINE cannot be changed”

If you are trying to disable an Outlook 2007 add-in, you might see this message “The connected state of Office Add-ins registered in HKEY_LOCAL_MACHINE cannot be changed”. Some users try to run Outlook as Administrator to work around this issue. We do not recommend doing so. Instead, you can disable this Add-in by modifying the registry.

  1. Run regedit*.
  2. Navigate to “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ Outlook\Addins”.
    (If you are running a 64-bit verion of Windows, you may also need to look in “HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\ Office\Outlook\Addins”).
  3. Look at all subkeys of Addins. Those are Add-ins you have installed. To disable a particular Add-in, set its “LoadBehavior” key to 2.

* – as always be very careful while performing registry modifications.

Do not forget to restart Outlook after making these changes.