When you minimize windows media player you can either have it in the task bar just like other windows or you might want it to dock in the taskbar with the play button, pause button, stop button etc. You will also have the video and the visualization window .So in order to do this, follow these instructions:
Right click on the task bar in the empty area (not over any minimized window) and then select toolbar.
Then check windows media player.
From now on when you minimize windows player, it will still be fully functional and will be docked in the task bar.