If you run multiple user accounts with Vista, you can encrypt files so only your user can access them. In this guide you’ll learn how to easily encrpyt and decrypt files in Windows Vista.
Download the Registry Hack
If you don’t feel confident working with the Registry Editor, you can download this registry hack. Simply extract the file and double click on EnableRightClickEncryptFiles.reg. To disable the Encrypt Files option, double click on DisableRightClickEncryptFiles.reg
Please Note: This guide involves working with the Windows Registry. If this is your first time editing the registry, please read this guide to get you started.
Add Encrypt & Decrypt to the Right-click Menu
1. Press Start, type regedit in the search bar and press Enter (or press Winkey+R)

2. Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
3. Create a new DWORD value named EncryptionContextMenu and set the value to 1

In order for this to take effect, you may need to restart your system.
Encrypt File Option on Right-click Context Menu

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