Protect Your Folder without any Software

(1). Go to Folder Options > View.

(2). There is last option called "Use Simple File Sharing (Recommended)".
Uncheck it then click "OK".

(3). Open the Properties of folder which you want to protect.

(4). Go to tab "Security". There are listed "User Names" who can access that folder as written under: "Group OR Usernames"

(5). Now, Click on Advanced and Uncheck
“Inherit from Parent the permissions entries that apply to child objects. Include these..........."
And Click on "Remove" then OK.
Now, try to access that folder, you will not be able to access it.

Now to access this folder:-
(1). Open Property > Security > Advanced >
& check that option
"Inherit from Parent the permissions entries that apply to child objects. Include these..........."
2) Click OK.

Now you able to access that folder again.