Full-disk encryption software encrypts an entire drive, not just a few files or folders. Encrypting your computer's drives keeps your private data away from prying eyes, even if your computer is stolen.
You're also not just limited to a hard drive. External devices like flash drives and external hard drives can be encrypted by disk encryption software, too.
Windows and macOS both have integrated whole disk encryption programs—BitLocker and FileVault, respectively. In general, we'd recommend that you use those tools if you can. If you can't for some reason, or if your operating system's included tool doesn't offer a feature you'd like, one of the free programs below might be for you. You can instead encrypt only some of your files.
Portable version available.
Can be unnecessarily complex at times.
Based on the popular (but discontinued) TrueCrypt software is VeraCrypt. It's a powerful disk encryption program that supports hidden volumes, on-the-fly encryption, keyfiles, keyboard shortcuts, and more awesome features.
Not only can it encrypt whole disks of data at once, but it can also encrypt the system partition that has an OS installed. Furthermore, you can use VeraCrypt to build a single file that acts as a drive, complete with its own encrypted files and folders.
If you're encrypting the system volume (the partition you're actively using), you can still carry on with regular activities while the process completes in the background. This is really nice considering how long it takes to run a full disk encryption on large amounts of data.
You can use this program in Windows, macOS, and Linux.
Free software that's easy to use.
Supports RAID arrays.
User interface is antiquated.
Additional tools aren't always helpful.
One massive glitch.
No update since 2014.
DiskCryptor is one of the best free disk encryption program for Windows. It lets you encrypt the system/boot volume as well as any other internal or external hard drive. It's also really simple to use and has some pretty neat, unique features.
In addition to password protecting a partition, you can even add one or more keyfiles to it for increased security. Keyfiles can be in the form of files or folders and, if set up as such, are required before mounting or decrypting a volume.
Data on a volume encrypted using DiskCryptor can be viewed and modified while the drive is mounted. There is no need to decrypt the whole drive just to access the files. It can then be dismounted in seconds, which renders the drive and all data on it unusable until the password or keyfile(s) are entered.
Something we particularly like about this program is that if your computer reboots while a drive is mounted and readable, it automatically dismounts and becomes unusable until the credentials are entered again.
This program also supports encrypting several volumes at once, can pause encryption so that you can reboot or remove a hard drive during the process, works with a RAID setup, and can encrypt ISO images to produce encrypted CDs/DVDs.
The only thing we don't like very much is that it has a major glitch that could render your encrypted system volume unusable. It's important to recognize this problem before encrypting a partition that's used to boot into Windows. More about this in our review.
DiskCryptor works on Windows 11, 10, 8, 7, Vista, XP, and 2000, as well as Windows Server operating systems.
USB authentication supported.
Straightforward program without unnecessary extra features.
Only one password.
Won't work on Windows 11/10.
The system drive, as well as any attached hard drive, can be encrypted with COMODO Disk Encryption. Both drive types can be configured to require authentication by password or a USB device.
Using an external device as authentication requires it to be plugged in before you're given access to the encrypted files.
One thing we don't like about COMODO Disk Encryption is that you can't choose a unique password for each encrypted drive. Instead, you must use the same password for each one.
You can change the initial password or USB authentication method any time you want but it, unfortunately, applies to all the encrypted drives
Windows 2000, XP, Vista, and 7 are supported. COMODO Disk Encryption will unfortunately not work in Windows 8, 10, or 11.
Updates shouldn't be expected because the program has been discontinued since 2010.
Encrypting NAS Drives
That Network Attached Storage drive you've got in the corner also supports encryption, but before you install encryption software, explore whether the NAS itself supports on-board encryption. If more than one computer accesses the NAS, it's generally more efficient to let the NAS manage encryption than to require each client computer to manage a shared encryption space simultaneously.