I've got two users in my department who are running Windows XP.

One user, when he presses alt-tab, gets the same kind of task switch screen that you get in Windows 2000. The icons for the applications, with truncated versions of the window names.

The second user, when he presses alt-tab, gets a mac-esqe screen showing miniaturized pictorial versions of each application's window. Very useful if you have a lot of windows open with similar window names. You can tell instantly, visually, which one is which, without having to parse the truncated window name.

User one covets user two's feature. User two doesn't recall having to do anything special to make this happen. Does anyone know how this gets enabled?