Solved Windows 8.1 invisible hard disk usage?

Right here goes, my first post, please be gentle with me.
I have put a 120Gb Intel SSD in my laptop, done a fresh install of Windows 8 from the supplied recovery DVD's. Then upgraded to Windows 8.1 through the Windows store, installed Photoshop 7 and Kingsoft Office and a couple of very small other programs. Everything is working fine. Great. I have hardly any docs music etc on this machine (they are all on my server).
I checked my hard drive usage and discover that I have used 75.3Gb and only have 31.2Gb left. C: partition is 106Gb. I know that the recovery DVD's created restore partitions and they can be seen in disk management. No worries there, they are only a few Gb and make up the total usable disk space (120Gb or so)
So I have been looking for where the bloat is. I have enabled viewing hidden files, and added up all the folders sizes on the root of C: It comes to 44Gb. It doesn't add up to anywhere near the total that I am being told is used 75Gb.
So what is using the additional 31Gb or so? and how do I find it?
I have attached a screenshot showing properties of "all in c:/" and properties of "Local Disk C"
As you can see, they are very different.
Any help would be appreciated.

Hi there
download TREESIZE Free or WINDIRSTATS -- these give a decent "Tree like" representation of what's using your disk space.

TreeSize Free - Quickly Scan Directory Sizes and Find Space Hogs

https://windirstat.info/

Cheers
jimbo

Thanks for that, a useful tool.
Looks like there's a 25Gb folder called "preload" in the root of C that I couldn't see with Windows explorer.
Any idea what it's for?
Screen shot attached.

You will have to go through that list. Preload is exactly that. It is so that Windows 8.x.x loads faster.

This is an useful tool too. Download DiskBoss 4.8.32

Desktop doesn't have the same issue

Thanks CountMike. I installed DiskBoss, but it doesn't show the "Preload" that is filling my drive like WINDIRSTATS does.
Correct me if I wrong, but Windows 7 didn't have a "preload"? I've never seen anything like it anyway.
Now here's another weird thing. I have a desktop, running Windows 8.1 Enterprise. Almost exactly the same set up as my laptop, same size SSD, Intel 330 series 120Gb, core i7 instead of i5, same programs installed. It has only used 40Gb and still has 71Gb free space and there is no "preload" folder hiding. I installed Windows 8.1 on this as a clean install from a Windows 8.1 bootable DVD, not a recovery DVD like my laptop.
I am baffled by this "preload" thing. I'm struggling to believe it is something that makes windows load faster. A 25Gb file? How can that make things faster? I'm thinking more and more it has something to do with the HP recovery set up.
Has anyone got any experience with "preload"
Screenshots of desktop attached.

OK, I think I have it worked out now. Most of the "preload" folder is used by a file called "install.wim" it's 21Gb. A quick google tells me it is a part of the recovery install software (a disk image me thinks). I am going to delete it. I suspect the recovery install won't work afterwards, but hey, I have DVD's so I don't care.

Success. I tried to use the HP recovery manager program to delete the recovery partitions (there is an option to do this) but after waiting for ages it didn't seem to do anything. Perhaps it is broken.
I have deleted the "preload" folder and all the recovery partitions. I used WINDIRSTATS to delete "preload" folder and Paragon Partitioner to delete all the recovery partitions.
Machine still works just as before (boots just as quick) and I now have what I consider to be the correct amount of disk space.
A big thanks to Jimbo45 for the link to WINDIRSTATS and setting me on the right path.
Now I will try and install Ubuntu 14.04 with Windows 8 dual boot. This I'm told will not be so easy.... but I guess that will be a whole other story that's not relevant to this thread. It used to be so easy with Windows 7. All the new UEFI stuff is complicated for me.

If you are not going to do a lot of twiddling with Bios and HW and if your computer has it, Legacy mode instead of UEFI can simplify things a lot.