Here’s a handy little feature that I find useful. If you ever play around with the size or location of the iTunes window and want to make it fit the screen better, simply follow the instructions:
If you’re on Windows: : hold Shift and either double-click the title bar or single-click the maximise button (The title bar is the small bar at the top that says “iTunes” in the middle.)
If you’re on Mac OS: : hold Option and click the Zoom (+) button
This’ll reset the size and position to its default for your screen resolution. Assuming you haven’t changed screen resolution since installing it, it’ll look just as it did when you first installed it — nearly filling the entire screen, but not quite. It’s also a very useful shortcut if you ever change your screen resolution.
Doing the operation a second time will move the iTunes window back to where it was before you started reading this article and messing with it. Simple!