How to lock folder by putting password or similar to that?

Answer 1

try Folder Lock

http://www.download.com/Folder-Lock/3000-2092_4-10598665.html?tag=lst-0-1

Answer 2

Download eazyzip (google search for download URL). It works as a compressed folder and will allow you to set a password.

Answer 3

if you're using windows operating system, you can try this:
-right click on the folder
-click sharing and security
-click the security tab
you'll see groups/user names there.. just deny (click the check boxes under "deny" which is seen below the list of users) everyone else except you!
simple as that! :D
that way, no one except you would be able to open/delete that folder
good luck dude! :D