Here's how you add Encrypt and Decrypt to right-click context menus.
1. Open the Start Menu and search for regedit or
Open Start Menu -> Run -> regedit
If prompted by UAC then click yes
2. In regedit go to
Code:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
i) In the right pane of Advanced right click on an empty space and click New DWORD (32Bit) and name EncryptionContextMenu and press Enter.
ii) Now in the right pane right click on EncryptionContextMenu and click Modify and enter 1 in Value Data
encrypt.png
And close regedit.
To remove just delete the EncryptionContextMenu DWORD (32bit) entry in the right pane.