How to use the quick preview bar of Windows7?

Q: How to use the quick preview bar of Windows7?
A: In the XP era, when we selected the image file, we can see the preview effect of the image on the left side of the file manager. In the era of Vista, Microsoft ported this feature to the right side of the file manager, which turned into a sidebar alone, and expanded from the original preview image to video and video previews. But under Windows 7, we can't find this preview feature!
Don't worry! This feature is not lost! But the default Windows 7 does not open it. We can easily turn it on and off with a single button. At the bottom of the file manager search box, there is an icon. Let's click to see if the preview bar is out?!

Not only that, but we can also use the shortcut keys to turn the preview on and off. The shortcut key is alt+P, and friends who have Windows7 can try it out by themselves.