You might have an instance were a user or customer need to be able to see attachment in Outlook. This solution below is one of many different ways but this one made the most sense for me casue it could be controlled by a GPO.

1. Go into registry @ ‘regedit’ (run as admin, if you search for it)

2. Then navigate to this location depending upon your flavor of Office:

3. Verify that the following registry key for your version of Outlook exists.
Microsoft Office Outlook 2010 – HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\O utlook\Security

Microsoft Office Outlook 2007 –  HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\O utlook\Security

Microsoft Office Outlook 2003 – HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\O utlook\Security

Microsoft Outlook 2002 – HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\O utlook\Security

Microsoft Outlook 2000 – HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Ou tlook\Security

4. Then just make a String key and call it ‘Level1Remove’ and click ok.

5. Then right click it and press modify and say you need to unblock a .url or a .exe you enter those in separated by a semicolin and no space like this : ‘.url;.exe’ and press enter.

6. Restart Outlook if it’s still open.

7. Whalla now you can open previous blocked attachments that Outlook automatically blocks by default once you restart Outlook.