If you are in a situation where you need to lock or hide files, then you might want to consider storing them off site, and not on your computer...safer all around
So, the issue is that you know that there are files in a given folder, but they are hidden from view...and now you want to expose them to view and access them...is that it?
Unless you have the access code, your up a stump. Or, if no code, then try to gain "ownership" of the folder and its contents... check here for a summary of how to: Search Results
But, if you do not have an NTFS and still operate with a DOS underlay, ie. FAT32, then you may still be able to access everything from the DOS setup on re-boot. Those hiding type progs usually have a safety switch accessible in DOS and activated when you set it all up.
WARNING! IMHO If you ever have an interest in the software "DEEPFREEZE" ...please be aware that you can lose your whole hard drive to it, if you mess up one little part of the process...been there, done that!!! IMHO