Windows XP Professional

• 1). Select the folder you wish to encrypt by left clicking it. Then, right click the folder and scroll down to click "Properties."
  
  
• 2). Click the "Advanced" button. Within the Advanced box, check the "Encrypt contents to secure data" option and choose a password.
  
  
• 3). Click "Apply" and then "Ok" to complete the encryption.
  
  

Windows XP Home and Older Windows Versions

• 1). Download TweakUI to your computer, available as a free download. Open the program once installed.
  
  
• 2). Select "Explorer" in the TweakUI window.
  
  
• 3). Locate "Show 'Encrypt'" on context menu (found inside the Settings tab which is in the right side of the window), and check the box. This option should be below Prefix "shortcut to" on new shortcuts and above "Show 'View workgroup computers'" in NetPlaces.
  
  
• 4). Select the folder you wish to encrypt and right-click the folder. Click Properties. Click the "Sharing" tab and check the box that reads "Make this folder private." Click "Apply" and then "Ok."
  
  

Mac File Locking

• 1). Open up the "Disk Utility" application and click through the menu options "File," "New," and "Disk Image" from "Folder."
  
  
• 2). Choose a folder to protect and then choose "AES-128″ encryption. Press "Save."
  
  
• 3). Enter your desired password twice.