First of all, use your account to log in Win 10. Right-click on the file/folder you want to encrypt and then click Properties. Click the General tab and then Advanced. Select the Encrypt contents to secure data check box, click OK, and then click Apply. Choose Encrypt the file and the parent folder or Encrypt the file only, click OK and then OK again. After these steps, the file/folder should be encrypted.
To decrypt this file/folder, you need to repeat the step 1-2-3 above and then clear the Encrypt contents to secure data check box. Then click OK and OK again.
If it is your first time to encrypt a file/folder, an encryption certificate will be automatically created, and you had better back up your encryption certificate for fear that certificate and key are the lost or damaged. Click Back up your file encryption and key – Back up now in the pop-up window, click Next and Next again. Tick the password box, type your password in the blank, and click Next. Click Browse… to specify the location of this file, click Next and then Finish. Then the certificate file will be saved on the specified place. Otherwise, you can open Windows Edge, click Tool menu – Internet options, click on Certificates in Content tab, select the encryption file and click Export – Next. Then select Yes, export the private key, click Next and enter a password to continue the rest steps.
For more Windows information, click here.
When other users of this computer log in and try to open this file, there will be a pop-up dialog that shows “You don’t currently have permission to access this folder”. So if you want to allow someone to have the access to this encrypted file, you can click Details beside the Encrypt contents to secure data check box, click Add… and then Find User to search for the user you wish to add to this file. But you have to make sure he has valid EFS certificate to this encrypted file, or you will receive the error message shown “No appropriate certificates correspond to the selected user”.