Windows 10: Unexplained disk space usage

So I got a new Dell laptop with 120GB SSD, and I installed Windows 10 on it. After installation I had 90GB free space, and that seemed normal because I thought it needed space for all the system files. Then I installed Visual Studio and some minor programs and I was at 70GB. I though it wasn't a big deal yet. Then I installed a few more minor programs, none of which exceeded 5GB in total, and now I'm at 49GB free space. That's when I started worrying something might be wrong. I asked some tech guy I know about it and he said that Windows 10 saves backups of files or something and that I need clear temp files or something. I didn't quite understand him, so I'm posting here in case someone else knows what to do.
Any ideas?
Thanks

:)

 

Unexplained Disk Space Increase

Thanks man. I should have paid more attention to the terminology.

Regarding the problem i have seen it with hidden files also but it is nowhere near the 400 gb mark.

 

Unexplained Disk Space Increase

First, please note that the term "memory" is used to refer to the place where the computer holds the program and data it is working with at the moment. It's normally random access memory (RAM), but that can be extended with the page or
swap file on the hard disk. The word "memory" is never used to refer to the space on a drive (whether that's a hard drive, SSD, diskette, CD, DVD, or thumb drive). Space on a disk drive is normally called "storage" or simply "disk space."

Calling disk space "memory" isn't so much wrong as just unconventional. In a sense, disk space is, of course, memory, but the important thing to realize is that the word is never used that way, and if you do so, you do it at the risk of seriously confusing
your audience.

Regarding the amount of disk space you have in use, first be sure you don't have files hidden
(see How to Show Hidden Files and Folders in Windows 7, 8, or 10), then
please post a screen shot of the C: drive in "This PC."

 

Check your shadowstorage. Use this command in an elevated command prompt

vssadmin list shadowstorage

If it is quasi zero, then we are on the wrong track.

 

It says 'no items found that satisfy the query'

 

That is a bit strange, but so be it. And you are sure you used admin mode.

 

You can check first, where your disk space is.
You can do it with Settings/System then pick Storage and click on C: drive
You will get list like this, which you can explore further.
For more detailed view, use third party program like treesize free or similar.

 

I guess I forgot to mention that I also installed Windows 8 and then upgraded to Windows 10.
Turns out it was keeping 26.5GB of temporary files as previous versions. Deleted those, seems fine now.
Thanks anyway

 

If this was the Windows.old file which the Upgrade created to back up your Win8 state, you can no longer roll back to 8, so it's 10 for good now.*Party

 

WinDirStat - Windows Directory Statistics