Whether you want to encrypt an entire hard drive or just a folder or a few files, using the right tool is vital.
On any given installation of Windows Vista or 7 Ultimate or Windows 8 Pro, there is a neat little built-in feature for encrypting drives called BitLocker. Although it has its uses, like operations involving the encryption of your system drive, a Trusted Platform Module or TPM chip is required. Some business-grade laptops and desktop motherboards supply this hardware, but not everyone has access to a TPM.
Perhaps full disk encryption is not the goal here, and you want to encrypt files on an individual basis rather than partitions, or you want to create virtual mountable "encrypted disk" files that you can tote around and attach at will, whenever you need to drop or grab a file. Whatever your end goal, I will show you five apps for disk and file encryption that will get the job done handily, no matter the task.
Make no mistake; TrueCrypt is one of the most popular freeware alternatives to BitLocker for whole-disk encryption. You can protect all of your drives with high-grade AES and Blowfish encryption schemes, prevent pesky snoops from peeking inside files and even incorporate highly secure boot-strapping. If you are extra paranoid, TrueCrypt can even create a dummy partition with a separate key you can divulge under duress, keeping your confidential partition from ever seeing the light of day. As an added bonus, TrueCrypt is multi-platform and not simply limited to Windows machines.
2. Kruptos 2 Professional
If you are looking for something that takes care of file encryption, Kruptos 2 Professional does a nice job here with its easy to use interface and quick performance. You can also create encrypted ZIPs and self-extracting EXE files as well as secure deletions so that files cannot be recovered so easily. Before running the application, it's advisable to run it as Administrator in order to avoid any file-write errors that could come up in some directories.
3. Privacy Drive
For whipping up secure data containers that can be mounted to your computer for easy and secure access, in a way similar to TrueCrypt's encrypted containers, Privacy Drive accomplishes the task. It has a clean and simple user interface that incorporates fancy pie graphs for encrypted disk space information and other extras.
4. GNU Privacy Guard (GnuPG)
If you insist on only using fully open-source software, GNU Privacy Guard seems fairly competent at handling file encryption. The software seems to be spread out over many tools, but the Windows GUI portion of GnuPG seemed easy enough to get around. You can also manage root certs for S/MIME emails and a key manager to keep all your custom keys safe for use.
Some encryption tools opt for the extremely sparse and no-frills approach to design by residing exclusively in the right-click context menu for Windows Explorer. This is where AxCrypt comes in. Simply select files you want to encrypt, right-click and select your preferred encrypt / decrypt operation you wish to perform. Just because it might appear simple looking, doesn't mean that it lacks in features though. It feels just as competent as most of the previous apps listed.