Not sure if you are on a dual setup or not (i.e. duplicate of the monitor or extended desktop), but if you are on extended desktop, I have found that certain players have no problem going over to your secondary display (i.e. t.v., second monitor, projector) and then being put in full screen mode while your primary display (usually your laptop screen from most people) remains usable for other tasks. This also solves the problem of having to constantly switch resolutions. Some players that I have found to work well are windows media player, Divx Player, and intervideo windvd. Some players, like the last version of the core media player that I tried, will not work this way and will always insist on using your primary display for full screen mode. The other thing to note is, at least with windvd (haven't seen this on any other players), some of the display modes cause my secondary display (which is a t.v. connected via s-video jack) to go completely black, but that was fixed by simply changing back the the default mode.