These keys are never reported (first failure in VBox.log)
Name: /VirtualBox/GuestAdd/InstallDir
Name: /VirtualBox/GuestAdd/Revision
Name: /VirtualBox/GuestAdd/Version
VBox.log section
00:00:14.663 Guest Log: VBoxService.exe: Error: Failed to query registry key (install directory)! Error: 0
00:00:14.790 Guest Log: VBoxService.exe: Error: No file information found! File = C:\WINDOWS\system32\VBoxGINA.dll, Error: 1812
00:00:14.790 VBoxService.exe: Error: No file information found! File = C:\WINDOWS\system32\VBoxOGLarrayspu.dll, Error: 1813
00:00:14.791 Guest Log: VBoxService.exe: Error: No file information found! File = C:\WINDOWS\system32\VBoxOGLcrutil.dll, Error: 1813
00:00:14.793 Guest Log: VBoxService.exe: Error: No file information found! File = C:\WINDOWS\system32\VBoxOGLerrorspu.dll, Error: 1813
00:00:14.795 Guest Log: VBoxService.exe: Error: No file information found! File = C:\WINDOWS\system32\VBoxOGLpackspu.dll, Error: 1813
00:00:14.798 Guest Log: VBoxService.exe: Error: No file information found! File = C:\WINDOWS\system32\VBoxOGLpassthroughspu.dll, Error: 1813
00:01:32.391 Guest Log: VBoxService.exe: Error: No file information found! File = C:\WINDOWS\system32\VBoxOGLfeedbackspu.dll, Error: 1813
00:01:32.391 VBoxTray: Started.
00:01:32.462 Starting host clipboard service
00:01:32.462 ClipConstructX11: X11 DISPLAY variable not set -- disabling shared clipboard
00:01:32.563 Guest Additions capability report: (0x5) seamless: yes, hostWindowMapping: no, graphics: yes
00:01:32.984 PCNet#0: Init: ss32=1 GCRDRA=0x02157420[64] GCTDRA=0x02157020[64]
00:02:30.179 Guest Log: VBOXNP: DLL loaded.