New security installed with Outlook 2002 SP1+ prevent certain extensions from being accessed when attached to emails. Use this tweak to modify that setting.
Navigate the the location below in your registry.
Create a new REG_SZ value named Level1Remove and set the value to a semicolon delimited list of the extensions you want Outlook to allow again, for example, bat;exe;cpl;inf.
Be sure not to include any periods in the list of extensions.
Key:[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Security]
Value Name: Level1Remove
Data Type: REG_SZ
Data: (semicolon delimited list of extensions (no period) to allow,
bat;exe;inf; )
