What is Disk C doing?

Question

Windows

The hard drive is divided into 2 logical partitions C - 100GB and D - about 900GB, if you go to drive C and measure the weight of all folders, you get ~ 55 gigabytes, but in the "My Computer" window it shows that drive C is occupied by 91 gigabytes, earlier there was a VirtualBox virtual machine on the computer, the program was later removed. I believe that something left by the virtual machine can occupy this place.
How to find remove excess trash and free up space?

Answer 1

Scanner
www.steffengerlach.de/freeware

Answer 2

Windirstat

Answer 3

Boxing usually stores data in my docks folder.... Look there.
Do a disk cleanup, with old updates and system restore points cleared

Answer 4

fsutil volume allocationreport C:
Also see how much space shadowcopy takes up.
If indexing is enabled, the index file can be tens of gigabytes in size.
can compress

"C:\Windows\SysWOW64\esentutl.exe" /d %AllUsersProfile%\Microsoft\Search\Data\Applications\Windows\Windows.edb