'always ask before starting download' check box

From: kate (anonymous_at_discussions.microsoft.com)
Date: 08/31/04 

Date: Tue, 31 Aug 2004 02:01:11 -0700

hi. not sure if i've got the right group here, but
thought i'd ask anyway. the box that comes up when you
download something asking whether you want to save or
open it no longer comes up on my computer cos someone
unchecked the 'always ask' box. how do i get it back?
thanks guys.
kate.