By default, Outlook XP (part of Microsoft Office 2002) won't allow you send or receive certain types of attachments. The rationale is that these documents can contain viruses or other harmful code, but the fact that Outlook doesn't let you disable or at least customize this feature is a little bit strange.

To enable executable attachments, follow the next steps:

1. To open the Registry Editor click on the Start button on your taskbar, then click on Run and type "regedit" and click on OK to start the utility (see picture 1).
    

   Picture 1

2. Expand HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Security (see picture 2).
   
    

   Picture 2

    

3. Create a new String and name the new value "Level1Remove" (see picture 3).
   
    

   Picture 3

    

4. Double-click the new Level1Remove to edit it, and enter the filename extensions you'd like to stop Outlook from blocking. Extensions should be typed in lower case, without the dots (.), and separated by semicolons (;). For example, type: exe;mdb;vbs to allow .exe, .mdb, and .vbs attachments, respectfully.
    
5. Click Ok and then close the Registry Editor when you're done. You may have to restart Outlook for this change to take effect.
   
   Note: I shouldn't have to tell you that this means you'll now be able to receive EXE files and other potentially harmful file types over email. Even though the majority of viruses are actually contained in Word documents (.doc files), you'll want to excercise some caution when opening any EXE files you.