If you're running windows xp you can hide the folder.
1: Right click on the folder and select properties.
2: A new window appears with the properties of the folder.
3: The the "general" tab, select the hidden attribute (its a check box).
To prevent other users of the computer to use the folder...
1: Click the "sharing" tab in the folder's properties window.
2: Check the "Make this folder private" check box.
This will prevent other user from logging in and messing with the folder. If someone logs in as you, then they will still be able to alter the folder.
There's not much else windows xp would let you do. You could always put the folder on a thumb/usb drive and carry it around with you.
or gumamit kayo ng Folder Lock Password kagaya
nito http://instantlock.net/download.asp