On a computer with Windows 8 installed, you should be driving the mouse over the document you want to encrypt, in this case, the so-called "test". Now, go to the "Properties" file and click on "General" and there, at the bottom, you click on "Advanced".
In the popup window that appears, you have to check the option "Encrypt contents to secure data".
Now, Windows will ask if you want to encrypt the file only or also the folder that contains it. The alternative that offers more security is to protect both the document and the directory in which it resides.
Now, you have the document "proof" encryption. What you distinguish the files that have no security measure because the name appears with a green source, as you can see in the picture.
This encryption offered by default the Windows operating system, called EFS, is not infallible. So if we compress the document, it will lose its protection. A popup window warns you of this if you try to enable the .zip understanding.