Cannot delete files and directories on Windows XP

For the last few weeks, I was annoyed by the fact that some of my directories on my Windows XP Pro machines cannot be deleted and they have been taking up lots of storage space. I kept getting the message: “Cannot delete xxxx: Access is denied. Make sure the disk is not full or write-protected and the the file is not currently in use.” I didn’t know how it got to this state; it was really frustrating. My google search gave me a few tips including changing the file/directory permission and ownership. They didn’t work until I ran into the Unlocker software. This program really did the trick for me. I still don’t know how Windows XP managed to put these file folders in this “locked” state.