You can use Folder Lock. Some of its features are Folder Lock is a fast data encryption and password protection software for Windows.
It can simultaneously encrypt, lock and password protect your files, folders, drives, USB drives and even CD/DVD-RW.
Folder Lock creates encrypted storages called 'Lockers'. You can keep as many of your private files and folders in your Locker and password protect it with a single click. You can transfer, secure and backup these Lockers.
Lockers are even undeletable on the computer where Folder Lock is installed. You can treat Lockers just as you would treat them in physical world.
With Folder Lock, you can choose either to encrypt using 256-bit AES on-the-fly encryption or lock files, folders and drives anywhere on your computer.
Each Locker can contain your encrypted files as well as your personal list of locked items. Furthermore, Folder Lock's options like hack monitoring, stealth mode, data shredding, history cleaning & auto protection, portable USB autoplay feature and virtual keyboard can enhance data security beyond anything ever achieved. In addition, a locker's delete, move and rename are password protected to prevent data loss.
Whether it's privacy, data theft, loss, leaks or intrusion attacks. Folder Lock secures your data in one fell swoop.
But it is
NOT free
link:
http://www.newsoftwares.net/folderlock/