Why does deleting a folder from Temp bring down the system?

Question

Windows

Hello. When cleaning Windows 7 SP1 Pro x64 from temporary files in the c:\Users\xxx\AppData\Local\Temp\ folder with the "Wise Disk Cleaner" program (I have been using it for a very long time on many computers, there were no complaints), the "mountWHD" folder was found about 13 GB in size (which, apparently, is also detected by the Disk Cleanup system utility). After partial cleaning of this folder, Office 2017 stopped working, in the "Start" menu, the "All Programs" list sharply "lost weight", and programs are launched from shortcuts on the Desktop (this is what we managed to find so far). Searching the Internet for the folder name turned up nothing.
Therefore, the question arises: what is this folder and why is it in Temp if deleting it brings down the system?

Answer 1

Because for some reason you have a file with a virtual disk there, which you apparently use.

Answer 2

Go to computer management and see what drives you have mounted (well, or in which folder).
Extension vhd or vhdx

But really this is some kind of strange assembly