text: how do you put a password on a computer folder, or is their a free program that does it? i want to put a password on my folders, but dont know how to do it, you can use a zip folder but that only locks the files but not the folder. with windows xp professional, you can help protect private customer and financial information by using its encrypting file system (efs). when you encrypt a file or folder, you are converting it to a format that can't be read by other people. a file encryption key is added to files or folders that you choose to encrypt. this key is needed to read the file. windows xp professional makes the encryption and decryption process easy—simply follow the steps below to encrypt your files or folders. when you are logged on to your computer, you'll be able to read them. anyone who tries to use your computer without your logon will not be able to read them. to encrypt a file or folder click start, point to all programs, point to accessories, and then click windows explorer. right–click the file or folder that you want to encrypt, and then click properties. on the general tab, click advanced. select the encrypt contents to secure data check box. encrypt contents to use secure data  apply to changes to this folder & subfolders & files . hit on ok   to decrypt a file or folder click start, point to all programs, point to accessories, and then click windows explorer. right–click the file or folder that you want to decrypt, and then click properties. on the general tab, click advanced. clear the encrypt contents to secure data check box.