Description of attachment security features of Outlook 2000 in Office 2000 Service Release 1/1a

When you apply Microsoft Office 2000 Service Release 1 (SR-1) to Outlook 2000, you receive new options that help you control attachment security. When you apply SR-1, you see a dialog box when you open an attachment from an e-mail message. You can specify file extensions that must be saved to disk, as well as the extensions that may be opened directly from the e-mail message.

Attachment security improvements were first made available in the E-mail Attachment Security Update. For more information about the original E-mail Attachment Security Update improvements, click the following Web address: Office 2000 SR-1 further improves dialog box warnings for attachments. With the new dialog box warning feature, you can specify which file extensions trigger the more secure warning.

To obtain SR-1, click the article number below to view the article in the Microsoft Knowledge Base: After you apply SR-1, two registry string values are used to store the list of file extensions. These two registry string values control the warning dialog box for attachments:

HKEY_LOCAL_MACHINE\Software\Microsoft\Office\9.0\Outlook\Security\RemoveWarningFileTypes

HKEY_LOCAL_MACHINE\Software\Microsoft\Office\9.0\Outlook\Security\AddWarningFileTypes

NOTE: The OldAttachmentDialog registry setting is no longer used.

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

By default, the Security key is not on your computer if you did not upgrade to Outlook 2000 from an earlier version of Outlook. If the Security key is not on your computer, you must create a Security key. To create a Security key:

1. Click the Start button, point to Run, and then type regedit to start Registry Editor.
2. Locate the following registry key:
   HKEY_LOCAL_MACHINE\Software\Microsoft\Office\9.0\Outlook
3. On the Edit menu, point to New, and then click Key. Name the key "Security" (without quotation marks).
4. Quit Registry Editor.

To make attachments bring up the more secure dialog box, use the following example.

NOTE: The "XYZ" and "ABC" extensions are examples. You can use any extensions that you want.

1. Click the Start button, point to Run, and then type regedit to start Registry Editor.
2. Locate the following registry key:
   HKEY_LOCAL_MACHINE\Software\Microsoft\Office\9.0\Outlook\Security
3. On the Edit menu, point to New, click String Value, and then add the following registry value:
   Name: AddWarningFileTypes
   Type: REG_SZ
   Data: XYZ;ABC
   NOTE: Extensions should be separated by a semicolon and should not include the leading period (.) character.
4. Quit Registry Editor.

Consider that the "BAT" extension is a built-in extension that normally brings up the more secure attachment dialog box. To make attachments with a "BAT" extension use the less secure dialog box:

1. Click the Start button, point to Run, and then type regedit to start Registry Editor.
2. Locate the following registry key:
   HKEY_LOCAL_MACHINE\Software\Microsoft\Office\9.0\Outlook\Security
3. On the Edit menu, point to New, click String Value, and then add the following registry key:
   Name: RemoveWarningFileTypes
   Type: REG_SZ
   Data: BAT
4. If the RemoveWarningFileTypes string value is not on your computer, use the same procedure to create the RemoveWarningFileTypes string value that you used to create the AddWarningFileTypes string value. Set the value data to a string that you can name, such as "XYZ."
5. Quit Registry Editor.

The following is the default list of file types that issue a security warning upon opening: NOTE: If you use the RemoveWarningFileTypes string value name, you must also create the AddWarningFileTypes string value name and set its data to a value that you can name, such as "XYZ." The RemoveWarningFileTypes string value requires the AddWarningFileTypes string value for it to work properly.