When logged in as a limited user, it should prompt like that anytime you
attempt to install a program. Contrary to how it may appear, this doesn't
allow the limted user to install the program --- it merely logs on a
"desktop-less" admin user and installs the program as if the admin user had
been logged in all along. If the install program happens to copy shortcuts
to any "all users" areas of the start menu / registry, then the limited user
can use that program after the install.
XP will not prompt like that to "use" a program that's already installed,
although in some cases it may be required to do something like that manually
(for instance, to run a program that makes registry changes while logged in
as a limited user). To get the authentication box to appear, you can hold
down Shift while you right-click a shortcut and choose Run As..., or you can
modify the shortcut's properties by going to the properties, Shortcut tab,
then click Advanced... Then select "Run with different credentials." Now it
will prompt for another user every time you use that shortcut.
Remember, when you're "running-as" another user in XP, the program thinks
that's the user that's logged in, so if you saved to "My Documents" while
running as Administrator, the file would not appear in the
currently-logged-in-user's My Documents folder. This also means that the
user running would have access to the run-as-user's files.
Windows Vista promises a new security system where you can set up protection
that raises the users' security level temporarily, rather than merely running
a program using another accounts' security settings. Of course this causes
havoc with lots of programs, and is one main cause of delay in the release of
Vista.
__________________
Shawn
