How can I decrease default zoom in iTunes?
Since installing iTunes 12.3.3.17 on Windows 10 the iTunes Store page completely dominates the screen.
How can I make zoom out so I can see everything including scroll bars?
Try changing the text size in windows. For Windows 7, right click on the desktop, screen resolution, Make text and other items larger or smaller, click on smaller-100%(default), apply, log off and then log back in. Open itunes and it should look the correct way. Itunes is not working correctly in windows when you change the size of text and icons.