Disk Defragment

Dear Sassy: I ran disk defragment on my computer last night. When it was finished, a message said there were 5 immovable files that could not be defragmented. What does this mean? How do I fix this problem?
~Still Fragmented

Dear Still: Sassy is sooo glad that you are running the Disk Defrag! Plus you remembered that it is a long process and ran it at night - great job! Let me start off by explaining a little about the defrag process... See the graphic below? Hypnotizing isn't it? The first image is a fragmented machine, steps are taken to move related files (or parts of files) so that they aren't separated. The ending image is a defragmented machine. Those are the basic steps to "defragging."

Sometimes files just can't be moved - like system files. These files can be moved but that is way above and beyond Sassy and really for our purposes these files can stay where they are.