Instead of using the [Security] DisableFileDwonload, which sets the Internet Options Security Settings File Download to Disable effectively preventing any file downloads including downloads that are opened in IE plug-ins such as Acrobat (PDF files) of Word (DOC files), use the PWB add-on PWBCloseWindow.
The PWBCloseWindow add-on will actively watch for windows being opened and close them before they can be interacted with. By using the add-on and telling it to close the "File Download" window, you can prevent downloading files via the IE "File Download" dialog, but allow downloads that open in IE plug-ins such as Acrobat.
--Scott
Preventing Downloads
Moderators: Tyler, Scott, PWB v2 Moderator