I know one method to encrypt the file and folder. 1) Open windows explore. 2) Now right click on folder and open it properties. 3) Go to general tab and click on advanced option. 4) Their is compress or encrypt attributes select the Encrypt contents to secure data check box, and then click OK. after this confirmation box will appear then select ok. But take care that if you want to only for folder then click on option only on folder. And another option is use folder lock.