Windows 2008 - 40 GB inaccessible space, used by system. Where?

Solution 1:

Did you try running spacesniffer as administrator like HopelessN00b suggests in the comments to your question? Usually, the big unknowns clear up and probably, you will find that the C:\Windows\WinSxS is the culprit. This is where Windows keeps different versions of .DLL files in an attempt to avoid the DLL hell of olden times. You can clean it up somewhat by doing this from a command prompt with administrator privileges:

• Dism.exe /online /Cleanup-Image /StartComponentCleanup - this starts a preen of all the files in the WinSxS folder. Depending on what you actually have installed, this may save just a little or quite a lot of space.

Check out this bit from MS on the subject. Also note that quite often, the command will fail with some error code. This usually means that there are pending operations on the folder (like Windows updates) that need to complete. Particularly, if there is a file called C:\Windows\WinSxS\pending.xml, it probably won't work. Let all updates install, maybe do a reboot and then try again. Hope it helps!

Solution 2:

I downloaded the VM and loaded it on a server. First thing I noticed was the C drive was compressed. If your physical server is like this, decompress the drive. There is little to gain by doing that.

After decompressing, I verified I'm seeing what you're seeing. I also added disk space to match your 150 GB. I, then, installed Defraggler Portable and analyzed the disk. I started looking at the sectors to see what files where there and noticed $MFT occupying a large amount of space. After a little searching, I discovered CCleaner's Drive Wiper utility might fix this.

I started a wipe of the free space (1-pass). The software is showing "Wipe MFT Free Space" but the task will run for about 24 hours. I'll let it run and report back.

There's a lot of information to be found involving $MFT and CCleaner if you search. You may find a 'eureka' moment that will you get to the root of how this happened in the first place. I can only speculate at this point.

Update 1: The process was taking longer than expected and I attempted to boost performance of the vm but the progress bar stopped and the time remaining increased. I rebuilt the vm with more resources but it doesn't seem to make a difference. One option that is available: take a backup of the C drive and if the backup is in the 18-19 GB range, format or wipe the C partition and restore the backup. I'm suspecting a 3rd party disk tool is responsible for the $MFT files being in this condition.

Update 2:

All I've been able to do is show what is consuming the space. I haven't been able to free it. There are likely paid tools to help. If you know what partitioning software was on the system before EASEUS, that might help your cause, too. On the above screenshot, the "64% of drive" is based on the 68GB vm, not the full 150GB partition you have.