Stop application windows springing up uninvited from the taskbar?

[skylark53]

Does anyone know how to stop files that are open in some application, but safely on the taskbar, from springing up into full-size windows when you open a second instance of that application?

Examples are Word, Mozilla, Internet Explorer.

I'm not looking for workarounds for particular applications, but a system-wide fix that keeps things on the taskbar until you call them up. Thanks!

Sky