You can use BitLocker Drive Encryption to help protect your files on an entire drive. BitLocker can help block hackers from accessing the system files they rely on to discover your password, or from accessing your drive by physically removing it from your PC and installing it in a different one. You can still sign in to Windows and use your files as you normally would.
New files are automatically encrypted when you add them to a drive that uses BitLocker. However, if you copy these files to another drive or a different PC, they’re automatically decrypted.
BitLocker can encrypt the drive Windows is installed on (the operating system drive) as well as fixed data drives (such as internal hard drives). You can also use BitLocker To Go to help protect all files stored on a removable data drive (such as an external hard drive or USB flash drive).
You can also use BitLocker to encrypted a VHD or VHDX (virtual hard disk) file mounted as a drive. You can copy and move this VHD or VHDX file to any Windows computer as a portable encrypted container file. When you mount the VHD or VHDX file on a computer and try to open the encrypted drive for it, you will be prompted for your BitLocker password before it will open.
You can save files into this BitLocker drive for VHD or VHDX file when unlocked like any other drive, and lock or unmount the drive when you like to secure it.
This tutorial will show you how to create a portable BitLocker encrypted container file using a mounted VHD or VHDX file in Windows 7, Windows 8, and Windows 10.