Sony Vaio Duo (15GB+ Unaccounted For)

Good evening guys.
How are things with you guys.

In any case, I've purchased a new laptop that's using windows 8.1
I've been trying to optimize the HDD usage here.
This laptop comes with 256GB HDD.

The issue here is that, I've gone through everything and it seems that even though it says that I've used up 70GB+, i seem to calculate only 50GB+ usage. My question here, where is that 20GB (approx) used at?

Just in case I am doing it wrong;

To check how much space I've used, I've right clicked C: , Property
It says I've used up 73.8 GB
Free space 140 GB
HDD capacity 214GB

To check what the 73.8 GB consist of, I just have to go to Local Disk (C
and right click Property to every files that exist there;
- Intel [1.21MB]
- PerfLogs [0 bytes]
- Program Files [1.32 GB]
- Program Files (x86) [2.90 GB]
- sources [0 bytes]
- Update [22.5MB]
- Users [35.8GB]
- Windows [16.3GB]

Now if we sum those all up, we've got 56.32GB.
My question is, where is the rest of the 17.48GB being used at?
Is there any other location I haven't checked yet?

Additional Note;
Viewed 1 hidden file in the C:
- ProgramData [2.14GB]

So total we have about 58.46GB now
Still 15.34GB unaccounted for~

Read more: 20GB used unaccounted for (Windows 8.1) - Computers General - TechMantis Forums

 

~8 for page file and ~8 for hibernation?

 

WinDirStat - Permalinks to downloads and other content

good program

 

Note:
15.34GB unaccounted for.

Okay, I've downloaded the program and checked.
- hiberfil.sys = 6.3GB
- pagefile.sys = 1.9GB
They're both under this file called <Files> which takes up about 8.5GB

I've also noticed that there's this folder called 'System Volume Information' which takes up about 5.7GB

and strangely, it's stated in the program that 'Program Files [1.32 GB]' (Same one as above) now takes up 6GB -_-

Is there anyway I can 'delete' some of these files?
Or are they super important or something?

 

does the Duo have rapidwake like the SVZ has? If so, you can disable hibernation and recover those 6.3 gigs.

If you need more space, check to see how much space is being used by system protection and either disable to reduce the amount of space it can use.

Try running disk cleanup and make sure to click "clean up system files" afterwards to see what you find there. Make some crazy error log file or depending on how you updated your system either and old windows installation or service pack files.

 

just looked it up, DUO has rapid wake, make sure it's enabled and then disable hibernation. Not needed.

 

How do you enable it and disable hibernation?
(Sorry, first time using windows 8 here, not really sure what to do)

 

elevate command prompt

powercfg -h off

 

Also remember that your hdd/ssd size is not what it claims. see this site.

"for each Gigabyte that a drive manufacturer claims, they are over reporting the amount of disk space by 73,741,824 Bytes or roughly 70.3 MB of disk space."

A 256Gb drive formatted would actually only have 237.2Gb of space.

Also you may have space taken up by a hidden restore partition?