Why is my VirtualBox failing to boot?

VirtualBox is a popular open-source virtualization software that allows you to run operating systems like Linux, Windows, etc. in virtual machines on your physical computer. However, sometimes VirtualBox virtual machines fail to boot up properly and get stuck at the splash screen. There can be several reasons why this happens.

Common Reasons for VirtualBox Boot Failure

Here are some of the most common reasons why a VirtualBox VM may fail to boot properly:

Corrupted or Incompatible Virtual Disk Image

The virtual disk image (VDI/VMDK/VHD file) containing the virtual hard drive of the guest OS may have become corrupted or incompatible with the current version of VirtualBox. This can happen if the virtual disk image was created with an older version of VirtualBox or if the image file was manually edited outside of VirtualBox. Trying to boot with an incompatible or corrupt disk image will cause boot failure.

Insufficient RAM Allocated to Virtual Machine

VirtualBox allows configuring how much of your host machine’s RAM will be allocated to each VM. If you haven’t allocated enough RAM to the virtual machine, it may fail to boot properly. Each guest OS has minimum RAM requirements that need to be met. For example, Windows 10 needs at least 2 GB RAM. Setting lower RAM can lead to boot issues.

3D Acceleration Not Enabled

VirtualBox provides a 3D graphics acceleration feature that improves graphics performance for gaming and video requirements in the virtual machine. If your VM has a 3D-enabled OS (like Windows 10/8) and this feature is not enabled in VirtualBox settings, it may prevent the VM from booting properly.

VM Improperly Powered Off

If you force power off or reset a virtual machine without properly shutting it down first, it can cause file corruption and boot problems next time you start the VM. Always use the Shut Down or Close options in the VM for proper power off.

Storage Controller Not Enabled

The storage controller (IDE, SATA, SCSI, etc.) for the virtual hard drive needs to be enabled in the VM settings for the guest OS to detect the virtual disk on boot. If the controller is missing or disabled, the VM will fail to find the boot disk.

CPU Virtualization Not Enabled

Hardware virtualization features like Intel VT-X/AMD SVM need to be enabled in BIOS to accelerate virtualization. If this CPU feature is disabled, the VM may fail to boot properly. Check your system BIOS settings to enable it.

Boot Order Not Set Properly

The boot order decides the device startup sequence to load the OS. If CD/DVD drive is set before Hard Drive in boot order, it may fail to detect the hard drive boot volume. Ensure hard drive is first in boot order.

How to Fix VirtualBox Boot Problems

If your VirtualBox VM is stuck at boot screen, here are some things you can try to fix it:

Check Hard Drive Boot Order

Go to the VM Settings > System > Motherboard and ensure Hard Disk is first in the Boot Order list. If CD/DVD drive is first, it will try booting from that instead of the hard drive.

Allocate More RAM to VM

Increase the Video Memory and Base Memory allocated to the VM in Settings > System. Make sure you meet the minimum RAM requirement of the guest OS.

Enable 3D Acceleration

Go to Settings > Display and enable 3D Acceleration if you have a 3D OS like Windows 10. Restart the VM to load graphics drivers.

Enable Virtualization in BIOS

Check system BIOS for settings like VT-x/AMD-V and enable CPU hardware virtualization support. This is required for 64-bit guest OSes.

Reinstall Guest Additions

If existing Guest Additions installation is corrupted, unsafe device driver errors can prevent VM boot. Go to Devices > Insert Guest Additions CD image > Run installer to reinstall a clean copy.

Check Storage Controller Settings

Go to Settings > Storage and ensure the Hard Drive has a Storage Controller enabled for it (IDE/SATA/SCSI). The controller is required for boot volume detection.

Run VirtualBox Repair Tool

The VirtualBox Repair Tool helps fix issues with virtual machine registrations and VirtualBox configuration. Run it to repair any VM files corruption.

Re-create the Virtual Machine

If none of the above fixes help, recreate the VM with a new virtual hard drive. Make sure to allocate enough RAM/VRAM as per guest OS requirements.

Advanced Troubleshooting

For more advanced troubleshooting, you can try:

Check Integration Services

Open command prompt inside the VM and run “sc query VBoxService” to check VirtualBox Integration Services status. If it shows as not running, make sure Guest Additions is installed properly.

Verify Hard Drive Integrity

Attach the VDI/VMDK/VHD file to a working VM or use qemu-img check command to check for errors. It will attempt to repair any issues found.

Boot in Safe Mode

For Windows VMs, use F8 during boot to enter Safe Mode. This will load minimal drivers and help isolate issues.

Disable Antivirus and Firewall

Some security software may interfere with VirtualBox components. Temporarily turning them off may help rule them out as causes.

Check System Event Logs

The Windows Event Viewer logs will provide detailed error messages about causes of boot failure like missing drivers, disk errors, etc.

Update BIOS firmware

An outdated system BIOS may have issues with supporting hardware virtualization required by VirtualBox. Flash latest firmware for stability.

Change Graphics Controller

Try changing graphics chipset mode in VM Settings > Display. For Linux VMs, Nvidia driver issues may require changing to VBoxSVGA.

Best Practices to Avoid Boot Problems

Follow these best practices to avoid VirtualBox virtual machines running into boot problems:

  • Always shut down the VM properly before powering off host.
  • Periodically compact the virtual disk image files to eliminate fragmentation.
  • Keep VirtualBox version updated to latest stable release.
  • Install VirtualBox Extension Pack for maximum features support.
  • Disable dynamic resizing of disk images.
  • Set reserve memory allocation to avoid host-level page swaps.
  • Limit VRDP connections to VM for graphics stability.
  • Prefer fixed-sized disk images over dynamically allocated ones.
  • Make regular backups of VDI/VMDK/VHD files to restore in case of corruption.


VirtualBox boot failure is mostly caused by configuration issues like low RAM allocation, missing boot devices, graphics drivers conflicts, etc. Following best practices like proper VM shutdown, disabling dynamic disks, keeping VirtualBox updated and taking regular backups can help minimize boot problems.

When troubleshooting, check storage controllers, boot order, RAM allocation, 3D acceleration, Guest Additions and BIOS virtualization support. Repairing disk images or re-creating VMs may be needed in case of deep corruption issues. With a systematic approach, you should be able to resolve most VirtualBox boot failures.