> If you open an application when it's already open, Windows creates a whole new instance of the application instead of just switching to the already-open appl

> If you open an application when it's already open, Windows creates a whole new instance of the application instead of just switching to the already-open application. This can be handled by the application though. VLC for example has an option ("Allow only one instance") so that it will only let you, uh, open one instance at a time - if you try to open VLC again while there's a Window already open it just (IIRC) sets focus to the existing window. I think Firefox opening a new window is an intentional design decision.