You can check the keybind. Alt-O (Options) go to the Keys tab and change the drop down category to UI. Look for Toggle Player Window and see what the toggle key is or set a new one
If you still dont see it, then you might of slid the window off the screen. An easy way to get it back is to set the resolution to something lower and then set it back to your normal resolution. That should bring back all windows in view
|