The best way to protect your sensitive data is to encrypt them. SecretDrive is a free data encryption program that not only encrypts your data but also lets you store them in secure encrypted virtual drives.
SecretDrive allows you to create up to 8 encrypted virtual disks which behaves exactly like a normal hard drive partition but only shows up when they are mounted through the programs interface. Further, these drives can be encrypted on-the-fly using any one of five modern encryption algorithms - AES (Rijndael), Blowfish (256 and 448 bit), Twofish and CAST 256. Like physical hard drives, these virtual drives can be formatted, defragmented and performed all sorts of operations on them. It’s even possible to create encrypted containers inside virtual drives.
SecretDrive also supports creation of encrypted containers to be placed in flash drives and even temporary secure containers in the computers RAM.
The program includes some extra tools, such as a password generator, a secure file-wiping tool and an encryption tool that can encrypt text strings and standalone files. SecretDrive is similar to other file data encrytion tools like SafeHouse Explorer and My Lockbox, the difference is that SecretDrive mounts the encrypted containers and folders as virtual drives while other program do not.