To encrypt a file in Windows 7, navigate to the folder containing the file and use the Encrypting File System function provided by the Professional and Ultimate versions of Windows 7. Once the file is encrypted, back up your encryption key by utilizing the Certificate Export Wizard.

  1. Access the Advanced Attributes dialog box

    Use Windows Explorer to navigate to the folder containing the file you want to encrypt, right-click on the folder, and select the Properties option from the drop-down menu. In the Properties dialog box, click on the Advanced button.

  2. Encrypt the folder containing the file

    Check the box next to the Encrypt Contents to Secure Data option, and click OK. If you only want to protect access to the top-level folder, click on the Apply Changes to This Folder Only option. If you want to add a layer of encryption to every subfolder, click on the Apply Changes to This Folder, Subfolder and Files option, and click OK.

  3. Back up your encryption key

    Once the encryption process is complete, click on the Back Up Your Encryption Key pop-up in the lower right corner, and select the Back Up Now (Recommended) option to access the Certificate Export Wizard. Click on Next, and type in the password you wish to use to protect the encryption certificate. Choose a location where you want to save the certificate, and type in the desired file name. Click on the Save button, and click Next. Review the specified settings, and click on Finish.