The 3D Objects folder of Windows Explorer contains .3mf files which can be opened with Mixed Reality Viewer. The folder's default location address is
To remove this system folder, open the 'Run' dialogue box, type regedit.exe, and hit the Enter key to open the Windows Registry editor as Administrator.
Next, navigate to the following location by pasting the address into the address field:
Locate the tree node:
Now, to remove the folder from Windows Explorer, right-click on the entry, and select Delete.
If you are using Windows 10 64-bit, you also need to remove the key from another location:
Then, locate the following, right-click on the entry, and select Delete option:
That's it! Once you reboot you will not see the "3D objects" entry under "This PC" heading of Windows Explorer.