Version

7.2.12

Host OS Type

Linux

Host OS name + version

Linux Mint 22.3 (based on Ubuntu 24.04 LTS)

Host Architecture

x86

Guest OS Type

Windows

Guest Architecture

x86

Guest OS name + version

Windows 11 25H2 Build 26100.8875

Component

EFI

What happened?

The same Windows 11 virtual machine had been running successfully for a long time on a previous Linux workstation with an Intel CPU using VirtualBox 7.0.x. After migrating the VM to a new Linux workstation with an AMD Ryzen Threadripper PRO 9945WX, the problem appeared immediately and the VM no longer produces any video output. No changes were made to the guest operating system itself.

The problem is not limited to the migrated VM. Exactly the same behaviour occurs with:

• the migrated Windows 11 VM,
• a newly created Windows 11 VM,
• booting directly from the official Microsoft Windows 11 installation ISO.

In every case the VM starts, enters the RUNNING state, but only a black screen is displayed. The issue occurs even before the EFI firmware displays its first scrfeen, No EFI screen, BIOS screen or Windows boot logo is ever shown. The guest operating system is never reached; the problem appears to occur before the guest operating system starts.

Expected Result
The EFI firmware starts and the Windows installer or Windows Logon screen appears.

Actual Result
The VM starts but only a black screen is displayed. No EFI output is visible.

Additional Information

The following tests were performed:

• Reinstalled VirtualBox.
• Tested VirtualBox 7.2.12 and 7.1.18.
• Tested with and without the Extension Pack.
• Tested different graphics controller settings.
• Tested different CPU profiles.
• AMD-V initializes successfully.
• No Guru Meditation occurs.
• VBox.log contains no obvious graphics initialization error.

The VBox.log only contains the harmless message:

AHCI: Port0: No driver attached

which is expected because the Windows installation ISO should still display the EFI boot screen.

Comparison with QEMU/KVM

To verify that the guest installation and the host hardware are functioning correctly, the VirtualBox VDI was converted to QCOW2 and imported into QEMU/KVM on the same host.

Results:

• The Windows VM boots successfully.
• Windows reaches the BitLocker recovery screen.
• After entering the recovery key, Windows starts normally.
• Mouse, keyboard and networking function correctly.

In addition, a freshly created Windows 11 VM also boots successfully from the official installation ISO under QEMU/KVM.

This demonstrates that:

• the Windows installation is valid,
• the installation media is valid,
• AMD-V virtualization works correctly,
• the host hardware is functioning correctly.

The problem therefore appears to be specific to VirtualBox on this hardware/platform combination.

Oracle VM VirtualBox versions tested

• 7.2.12
• 7.1.18

The problem is identical with both versions.

Host System
Host OS: Linux Mint 22.3 (based on Ubuntu 24.04 LTS)
Kernel: 7.0.0-28-generic
Desktop: Cinnamon (X11)
Firmware: UEFI
Secure Boot: Disabled
CPU Virtualization: AMD SVM enabled
Nested VT-x/AMD-V: Disabled

Hardware
Lenovo Thinkstation 8
CPU: AMD Ryzen Threadripper PRO 9945WX
RAM: 64 GB
GPU: NVIDIA RTX PRO 4000 Blackwell
NVIDIA Driver: 595.71.05

BIOS
AMI BIOS Version: 2.22.0058
BIOS Date: 01/27/2026
Machine Type and Model: 30HHCTO1WW
AMD Secure Virtual Machine: enabled

How can we reproduce this?

The issue appears to be hardware- or platform-specific. It has been reproduced consistently on the host configuration described above but has not been verified on other hardware. Since the problem seems to depend on this particular hardware/software combination, it may not be reproducible on different systems.

VBox.log
inxi-system.txt
VBoxManage-showvminfo.txt

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.