By default Windows Operating systems does not allows you to lock individual folders with passwords. Means you can not password protect folders without the help of any third-party tools in Windows. However, in Windows there is a option to hide the folder, but it is no so useful.
Free Hide Folder
Free Hide Folder is compatible with Windows 9x/Me/NT/2000/XP/2003/Vista/7/8 operating systems. When you will run it for first time, it will provide option to set the password. Once, password is set for the tool, you are free to to protect your files and folder. When you will hide or unhide any files / folders it will ask to re-enter the password.
Lock-A-folder is the another free software that can be used to protect files / folders with password. Just like other folder locking tools, you need setup a master password in its first run. Once you have set the master password you are free to protect the files / folders with password.
Once you have set the master password, you can not uninstall it without the secret password.
Unfortunately, the developer has abandoned the project, meaning you won’t get any updates in future and also you will not get any replies to any queries.
HiddenDIR is another small freeware tool that helps you to protect your privacy by hiding in a few moves your private files/ folders. It will make invisible to anyone who has access to your PC, hidden folders visible only if you have access to the program that you can save in any directory or USB device.
SecretFolder can also be used for hiding / password protecting the files / folders from another users. It supports 32 bit / 64-Bit operating system as well as NTFS, FAT32, exFAT and FAT volumes are supported. It is also free to use and comes with easy user interface.