When in our house we only have one computer and everyone uses it, otherwise we have different user accounts, the desktop and My Documents can be a real mess, since everyone stores their files wherever they want, although sometimes, very rarely, users create an individual folder where they keep all their information.
The best way to solve this little big problem is to create different user accounts, so that each one can access their own version of Windows, which it will be completely different from the other users, since you can customize the interface, the wallpaper, the icons ...
But user accounts not only allow us to differentiate the use made by different users of the same PC, but also it also allows us to block access to our content, so that no one else can access it, as long as we have an Administrator account enabled, since otherwise anyone who passes in front of the computer will be able to access it without problems.
If your intention is to quickly block access to your data, photos, movies, the only option available in Windows is to add a password to the login and the only way to do it is by adding or creating an administrator account. On the Internet we can find applications that allow us to perform these functions, but we must not trust them since they do not fulfill what they promise.
To create a user account we just have to go to the Control Panel and click on Users. Within Users we will have the option to view and manage current users and administrators, as long as we are one of them, otherwise we will not be able to modify any menu option.
If we are administrators, we just have to click on its name and select add startup password, so that every time we start the computer, it will ask us for the password. But we can also quickly block their access if we are going to be absent for a while, by clicking on the start button and in the menu that allows us to turn off we select suspend or Change user.