Windows Guest(s) hangs during startup on Windows 10 host

[GylesG]

I have several VirtualBox Guests running on my Windows 10 Laptop, everything was working fine until last week.
Maybe a Windows 10 update that became active, but going back to a restorepoint of a week ago doesn't make it work again.

At that moment I was still using VirtualBox v6.1.8, so I upgraded to v6.1.24, unfortunately that did not provide a solution => No change.

All guests with a GUI are hanging (Win2012, Win2016 and WIn2019, but also Linux Mint 19.3), all others guests (CentOS 7, OL 6 and 7) are working fine, all 64-Bit.
On Windows the screen freezes on the logo, no "rolling-dots" are show and hangs, no heavy CPU load nore I/O on the physical machine.

I played around with HyperThreading (on <=> off), Display 3D Acceleration of guest, Processor settings (like PAE/NX), none of them worked.

I'm running Microsoft Windows [Version 10.0.19041.508] on a Dell Precision 7520 - i7-7700HQ @ 2.8 Ghz, 32 GB RAM
Using VirtualBox 6.1.14r140239 (Qt5.6.2), and even reinstalled it.

All advice, tips and tricks are welcome to solve this.

[scottgus1]

Hyperthreading should always stay on.

Pick one guest that exhibits the problem. Start the guest from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the guest from within the guest OS if possible. If not possible, close the Virtualbox window for the guest with the Power Off option set.

Right-click the guest in the main Virtualbox window's guest list, choose Show Log. Save the far left tab's log, zip it, and post the zip file, using the forum's Upload Attachment tab.

[GylesG]

Started this VirtualBox "Win2016PG" (OS is Windows 2016 x86-64), screen hangs / stops on Windows logo (no rolling-dots), no high load on the (physical) host.
A clean shutdown, e.g. with Windows Shutdown is not possible ... not started yet, so I had to "Power off the machine".

The next time "Preparing Automatic Repair" is appearing in window and shortly after that screen hangs / stop ... like before (on Windows logo).

If needed / helpful I can send other log-files, from my Windows Guests, because:
- Win2012 => see printscreen (uploaded) "Save the machine state" of "Power off the machine" are options.
- Win2016PG => Just hangs (see log-file)
- Win2019 => Is showing a dialogbox "VirtualBox - Guru Meditation" - "A critical error has occurred while running the virtual machine and the machine execution has been stopped" For help ..." after clicking "OK" the guest stops, when I click on "Ignore" this Window also hangs like the Win2010 (=> Windows logo, no rolling-dots). "Power off the machine" is the only option.

When uploading, I get "The file is too big, maximum allowed size is 128 KiB." => zipping.

[GylesG]

Uploading the Win2012 related files.

[GylesG]

Win2016

[GylesG]

Win2019

[GylesG]

Win2012 - Printscreen

[GylesG]

Win2019 - Printscreen (had to reduce the resolution to upload => The file is too big, maximum allowed size is 128 KiB.)

[scottgus1]

Pick one guest

(Indiana Jones:) "Salah, that's seven camels, I said, No camels! Can't you count?"

Hyper-V is enabled and needs to be disabled. See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

(The new test builds might have a fix for this problem. If you try a test build and it works, report here: viewtopic.php?f=6&t=90853, and save the installer file.)

[GylesG]

I verified the Hyper-V settings, via bcdedit

Windows Boot Manager
--------------------
identifier {bootmgr}
device partition=\Device\HarddiskVolume3
path \EFI\Microsoft\Boot\bootmgfw.efi
description Windows Boot Manager
locale en-US
inherit {globalsettings}
default {current}
resumeobject {17b6d514-b18f-11ea-ba57-e4b97a020fbd}
displayorder {current}
toolsdisplayorder {memdiag}
timeout 30

Windows Boot Loader
-------------------
identifier {current}
device partition=C:
path \WINDOWS\system32\winload.efi
description Windows 10
locale en-US
inherit {bootloadersettings}
recoverysequence {17b6d517-b18f-11ea-ba57-e4b97a020fbd}
displaymessageoverride Recovery
recoveryenabled Yes
isolatedcontext Yes
allowedinmemorysettings 0x15000075
osdevice partition=C:
systemroot \WINDOWS
resumeobject {17b6d514-b18f-11ea-ba57-e4b97a020fbd}
nx OptIn
bootmenupolicy Standard
hypervisorlaunchtype Off

It was already "Off" => hypervisorlaunchtype Off

I will try the test-build 6.1.15-140351.

[fth0]

I verified the Hyper-V settings, via bcdedit

Just to be on the safe side: You did this on the host (correct), and not on the guest (wrong), right?

[GylesG]

Yes, on the host / the physical machine, in my case my Laptop with Windows 10.

In "Windows Features" none of the checkboxes were checked in:
=> Hyper-V
==> Hyper-B Management Tools
==> Hyper-V Platform

I had to de-installed / removed the Linux-SubSystem (WLS) and rebooted.
All my Windows-VM-Guests are backup up-and-running, still a problem with a Linux Mint guest (32-bit), low priority and I'm going to upgrade to 64-bit anyway.

So Hyper-V was installed but not enabled, removing it (and WLS) did the trick.

Thanks for the assistance and feedback.

[pouldney]

Had similar problem WITH Ubuntu 22.04 and win10 guest.It would pause during boot and sometimes
Seize up the host .
I had the base memory set too high in settings - System.
Using system monitor while booting guest in the host I could see the memory getting neat 100%.