Securing confidential and personal data is always considered as a sophisticated task.You can use freeware third party softwares like Axcrypt, Disguise Folders etc to encrypt your data.If somehow you can’t use these softwares (installation restrictions) then you can secure your data using notepad.This trick works in windows xp,vista and windows 7.
Lock Folder without any Software
Open Notepad [Start-->Run-->Notepad]
In your Notepad just Copy/Paste the below CODE