IT:Outlook Express persistently tries to compact messages

From Stiki

The problem: every time that Windows starts up, you get the following error message...

Outlook Express
	To free up disk space, Outlook Express can compact messages. This may take up to a few minutes.
OK     Cancel

And the bizarre thing is that you may not even have installed Outlook Express!

Why this happens

Outlook Express is set to automatically display this warning message after having been opened 100 times. This is a default setting to ensure regular maintenance of old messages. But this doesn't explain why it appears even if you don't open Outlook Express.

You may notice that when the message appears, the corresponding application button on the taskbar has an icon of a magnifying glass. This is the icon for Windows Search.

Windows Search is installed as part of Service Pack 3 for Windows XP. By default this is set to search Outlook folders (as well as your documents and Internet Explorer history). When it searches Outlook Express, this counts as opening the Outlook Express application. When Outlook Express has opened 100 times, this triggers the warning on startup about compacting your messages.

Fix the problem

You need to perform both of the tasks below.

Just removing Outlook Express from the Windows Search locations will stop the Compact Check Count from incrementing in the registry, but since it has already reached 100 the message will continue to appear.

Just resetting the Compact Check Count to 0 will stop the message appearing for now, but after Windows Search has opened 100 times the message will reappear.

1. Remove Outlook Express from the Windows Search locations

1. Click 'Cancel' to get rid of the warning message. You need to close the message for the Windows Search icon to appear in the notification area.
2. Right-click on the magnifying glass icon in the task bar and select 'Windows Search Options...'. The Indexing Options dialog box will appear.
3. You should see 'Microsoft Office Outlook' and 'Microsoft Outlook Express' listed under 'Included Locations'. Press the 'Modify' button to change these choices.
4. From the Indexed Locations dialog box that appears, you can uncheck 'Microsoft Office Outlook' and 'Microsoft Outlook Express'. Press 'OK' to close this dialog, and 'Close' to close the Indexing Options dialog.

This stops Windows Search from looking at Outlook and Outlook Express, but the message will still appear since it has already been triggered.

If you can't change the above setting

You can alternatively use Group Policy to prevent Windows Search from indexing certain locations. This option is only available in Windows XP Professional since Group Policy is intended for businesses to configure Windows for multiple users.

1. Open the Group Policy application. The application file is gpedit.msc which is found in the Windows\System32 directory (usually this is at 'C:\Windows\System32'). Alternatively you can run the application directly from the Run dialog (from the Start menu select Run, or press Windows+R, then type "gpedit.msc" in the text box).
2. Navigate to "Local Computer Policy\User Configuration\Administrative Templates\Windows Components\Search".
3. Double-click on the setting 'Prevent indexing certain paths' to open it for editing.
4. In the dialog box that appears, select 'Enabled' (if it is not already enabled) and then click on the 'Show' button next to the text, "Prevent indexing certain paths".
5. In the Show Contents dialog box that appears, click on the "Add" button and in the Add Item dialog box, enter the following text:

outlookexpress://{*}/*

6. Close each of the dialog boxes by selecting 'OK' and close the Group Policy application.

2. Disable the warning message in the registry

This is a user setting, with the message appearing for each user independently, after that user has "opened" Outlook Express 100 times. The setting to adjust is therefore in HKEY_CURRENT_USER, but you can also check other users in HKEY_USERS.

You must cancel the Outlook Express warning message before carrying out the following steps. Otherwise your resetting of the count to zero will be overwritten by an incremented count greater than 100 as soon as you close the warning message.

To fix the current user:

1. Open the registry. You do this through an application called Registry Editor. The application file is REGEDIT.EXE which is found in the Windows directory (usually this is at 'C:\Windows'). Alternatively you can run the application directly from the Run dialog (from the Start menu select Run, or press Windows+R, then type "regedit" in the text box).
2. Navigate to "HKEY_CURRENT_USER\Identities\{GUID}\Software\Microsoft\Outlook Express\5.0" (where {GUID} is the globally unique identifier that represents your user ID on your computer; there should only be one choice under HKEY_CURRENT_USER).
3. You will see a registry key called 'Compact Check Count' and this will have a value of 100 or more. Double click on the key name to edit its value.
4. The Edit DWORD Value dialog box will by default show the number in hexadecimal (so it will appear to have a value of 64 or more). Set this to 0 and press 'OK'.
5. Close the Registry Editor.

You may wish to look at the equivalent entries under HKEY_USERS for other users, or perform the same steps above whilst logged in as any other user.