Encrypt files in secure, password-protected vaults.
The great news: Cryptainer LE is absolutely free software that creates an encrypted file area on your hard disk--whatever is inside is theoretically off-limits to snoops, spies, and federal agents.
Cryptainer also lets you create self-decrypting files, allowing you to send sensitive data to others securely.
The bad news: Cryptainer LE uses only 128-bit Blowfish encryption, so don't use it if your files absolutely, positively must remain unreadable. (Cryptainer ME, at $30, and Cryptainer PE, at $45 both offer near-unbreakable 448-bit Blowfish encryption). Encrypted volumes are also limited to a paltry 25MB unless you spring for Cryptainer ME (2.5GB) or PE (25GB).