If you want to secure your files and no one can view them if they do not have the password, TrueCrypt can do it for you.
It creates a virtual hard drive on your computer and only you will have access to this hard disk area, based on your password. You can keep here important and secret files. Only people that knows the password will have access to it.
You can create a virtual encrypted disk within a file, encrypt a real disk partition (that is not used by operating system) or encrypt the entire system drive (including Windows).
You can create a space/volume on hard disk that is visible or hidden.
Also, you can use a key file to access your secret files. This will prevent password guessing and will make almost impossible for someone who does not know your password, to guess it (manually or automatically).