System files taking up 50 GB?

[fuel1]

I have a Gigabyte P34W v5 laptop and my OS is on the 120 GB Samsung NVMe drive that came with it. At some point, my free space went from around 40 GB down to 17 GB without seemingly any indication as to why. I haven't installed any new programs. My W10 (came pre-installed with the system, not a manual upgrade) is fully updated.

I've tried optimizing the drive and using CCleaner, hasn't helped.

When I examine the drive under Settings --> System --> Storage --> This Drive, the breakdown is:

39.6 GB system files
2.39 GB virtual memory
6.35 GB hibernation file

Any thoughts?

 

[Colif]

I would expect the difference in size is probably a windows.old folder, they normally around 17gb. Have a look at option 1 here: http://www.tenforums.com/tutorials/2066-windows-old-folder-delete-windows-10-a.html
The anniversary edition of win 10 would have created one but it also should have deleted it after 10 days.

if its not windows.old, have a look at this to identify difference: https://windirstat.net/

20gb System files
1gb virtual memory
3.18gb hiberfil.sys

if you don't use hibernate and only use fast startup, you can reduce hibernate size in half (http://www.tenforums.com/tutorials/25151-hiberfile-type-specify-full-reduced-windows-10-a.html)