DiskCryptor for Windows

DiskCryptor can be used by most users. DiskCryptor will start in the background as a service with an icon in your system tray. If you wish, you can set it up to load from your boot section if you have encrypted your system drive. Clicking on the system tray icon will bring up a standard dialog box that allows you to encrypt/decrypt (AES256, Two-fish and Serpent), as well as mount or unmount encrypted drives.

These are the key features:

Support for SSD TRIM extension. Full encryption of external storage devices, such as USB drives and external HDDs.

DiskCryptor is lightweight and reliable. It doesn't have a significant impact on system performance. DiskCryptor can be used to encrypt only partition-level drives and drives.