Encrypt a File or Folder

The only secure way to hide your files is through encryption. Encryption turns your data into an unintelligible mess unless you have the password. Windows contains a built-in way to encrypt files, and ties the password to your user account—so you can only see the files if you’re logged in as the right user.Difficulty: Easy

Level of Obscurity: Low
Level of Security: Medium

You can see instructions for this in the “Encrypting Files Using the Encrypting File System” section of this guide (you’ll have to scroll down to the last section to see it). All you need to do is right-click on a file or folder, select Properties, go to Advanced, and check the Encrypt Contents to Secure Data checkbox.

The only downside to this method is that it links the encryption to your user account. That means if
your snooping sister tried to open the files from her Windows account, they wouldn’t open—but if you share an account, or if you step away from your computer while you’re logged in, she’d be able to see them just as easily as any other file on the PC. So make sure you lock the computer or log off every time you step away, or that encryption won’t stop anybody.