The thread discusses the limitations of Windows EFS encryption, which encrypts files at rest but decrypts them on-the-fly during access, allowing encrypted files to be viewable on Android devices when transferred. The original poster wants to prevent encrypted files from being viewable on other devices, even if copied, emphasizing the need for stronger encryption. The responder suggests using tools like VeraCrypt or TrueCrypt to create encrypted containers, or employing enterprise-level solutions like BitLocker with VHDs to better secure data during transfer and storage. Overall, the conversation highlights that Windows EFS alone doesn't provide foolproof protection when files are moved to other devices.