[1] 1 GB = 1,000,000,000 bytes. Actual user storage less.[2] Password protection uses 128-bit AES encryption and is supported by Windows XP, Windows Vista, Windows 7, and Mac OS X v10.5+ (Software download required for Mac).[3] Approximations: results will vary based on file size, resolution, compression, bit rate, content, host device, pre-loaded files and other factors.