Issue: Local Disk (C) has 168 GB of used space out of 200 GB, however only 142 GB of that is accounted for. The other 27.25 GB is nowhere to be found.

Folders in the Local Disk are listed below as well as how much space they currently occupy:
$AVG - 4 KB
ATI - 154 MB
Autodesk - 3 GB
MSOCache - 0 KB
PerfLogs - 0 KB
Perl - 39 MB
Program Files - 2.65 GB
Program Files (x86) - 75.5 GB
Program Data - 733 MB
Users - 36.8 GB
Windows - 23.7 GB
IPH.PH - 4 KB

By my count that adds up to roughly 142 GB.. so where is the other 26 GB?



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Also, I looked under Users. There were three folders: Default, Fred, and Public.
Default is 1.68 MB
Fred is 36.8 GB.
Public is 50 MB.

However upon examining the space used by each item within the folder Fred I found that only about 36.7 GB of the 38.9 GB was accounted for.
This isn't as big of a deal, but I would still like to know where that 2.2 GB is..

Anybody have any suggestions for figuring this out?

EDIT:
Made hidden folders viewable, updated the information.

EDIT 2:
Used a program called FolderSize to attempt to locate the data.
Well, I did discover that Empire: Total War was using 23 GB, so I uninstalled that game.
However, as before, the problem persists. Only now the numbers have changed from 118 GB accounted for out of 145 GB

The rest of that is probably shadow copies for system restore. Look in system information folder after giving yourself permission. Are you showing hidden system files? I only have 4 shadow copies. You may have many more.

-solved-

Thanks Suspended!
I was showing hidden files, however I did not notice the check box for displaying hidden system files. I unchecked it (therefore displaying system files), and found two rather large files that were responsible for 10 GB.

System Volume Information had 2 ghost backups, and the entire folder was 2.38 GB.

The mysterious 2.2 GB in the Fred folder has been found as well.

You will never get an exact count because there are other system files on the disk for partitioning, MBR, MFT, etc. These do not show up in Windows. There is an entry in the MFT for every file on the system:http://msdn.microsoft.com/en-us/library/windows/desktop/aa365230(v=vs.85).aspx.

A disk defragmenter like Auslogics will show you where each file is located relative to the beginning and end of the drive. Just click on a block to see which files are within that block. You will see that many files are reserved by the system and will not appear in Windows.
http://www.auslogics.com/en/

The Windows defragmenter leaves a lot to be desired. Defragment your system to give it a nice clean look.