A good way to avoid anyone from accessing your folders is to protect them using a password. This way, you will avoid anyone viewing or modifying their contents. Protected Folder is tool for exactly this purpose.
The program is easy to understand for any user. To protect your folders all you have to do is drag and drop them on Protected Folder's interface.
Once you install the application, you will be able to define a password that will provide access to the folders. This password can be modified from the application's options. Another available feature is the option to define if the protection also implies hiding the folder (you can do this for Windows Explorer as well as for other programs), or the impossibility to be able to read or write the file contents.
What's more, it also gives you access to an exclusion list as well as a set of simple options for the programs appearance.
Download Protected Folder so as to always keep the contents of your folders secure.