Windows 7 sports a handy feature, when selecting a file you can see its contents without opening any application.
This function is valid for images, photos, videos, text documents (files related to Office etc. ...).
Upon activation the file explorer will be divided into two parts.
Open Explorer choose a folder, Pictures, Documents, Video etc and make a click on Organize.
In the menu click on layout and then click Preview Pane.
Just move your mouse over the images and they will appear in the explorer.
Note that: In the preview pane, the file is in read mode, it is not possible to make changes.