Fix: Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)

Several VirtualBox users are encountering the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error whenever they try to open a virtual machine. Affected users report that this error occurs with multiple virtual machines (including any new ones that they try to create). This particular issue is confirmed to occur on Windows 7, Windows 8.1 and Windows 10.

Failed to open a session for the virtual machine. The virtual machine has terminated unexpectedly during startup with exit code (0x1).
Failed to open a session for the virtual machine.
The virtual machine has terminated unexpectedly during startup with exit code (0x1).

What is causing the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error

We tried to get to the bottom of this issue by investigating various user reports. Based on what we gathered and based on several solutions that affected users advertised, we have managed to identify several potential culprits that might trigger this particular error message:

  • The VirtualBox kernel driver is not installed (or is corrupted) – A couple of users have managed to get the issue resolved by reinstalling VirtualBox along with the VirtualBox kernel driver.
  • 3rd-party antivirus is interfering with VirtualBox – In a couple of reports, affected users were able to get the issue resolved by temporarily disabling the real-time protection of their 3rd party AV.
  • A bad Windows Update is causing the error – There’s one particular update that is confirmed to be causing this particular error. So far, this issue is only confirmed to occur on Windows 7.

If you’re currently struggling to resolve this particular issue, one of the methods below will enable you to resolve the issue. Below you have several fixes that other users in a similar situation have used to get the issue resolved.

Since the methods below are ordered by efficiency and severity, follow them in the order that they are presented until you find a fix that successfully resolves the issue in your particular scenario.

Method 1: Restarting your system

If you haven’t already done this, start simply by rebooting your machine. Several users have reported that after they rebooted their computer, VirtualBox was able to open virtual machines without being interrupted by the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error.

If a restart is not effective or you’re looking for a more permanent fix, move down to the next method below.

Method 2: Disable the antivirus while running the virtual machine

Another frequent culprit that will trigger the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error is an external antivirus suite ( a security option different than Windows Defender).

Several users that were using a 3rd party security suite have reported that the error doesn’t occur if the real-time protection of the AV is disabled. The steps of disabling the real-time protection are specific to each 3rd party antivirus, but you can typically disable it by right-clicking the taskbar icon and using the context menu.

Disabling the real-time protection on Avast Antivirus
Disabling the real-time protection on Avast Antivirus

An alternative would be to uninstall the security suite completely by removing the 3rd party security suite from your system. You can do this by following this guide (here).

Once the antivirus has been taken care of, open VirtualBox and launch the virtual machine again. If the AV was interfering with VirtualBox, you’ll no longer get the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error.

If you’re still seeing the error despite disabling your 3rd party security suite, move down to the next method below.

Method 3: Installing the VirtualBox kernel driver

Several users have managed to resolve the issue by reinstalling VirtualBox along with the VBoxDrv.inf (the VirtualBox Kernel driver). This approach seems to have helped a lot of uses to resolve the issue for good.

Some users have reported that just installing the VBoxDRV.inf driver was enough, but you’re better off re-initiating all of VirtualBox’s components. Here’s a quick guide through the whole thing:

  1. Pres Windows key + R to open up a Run Dialog Box. Then, type “appwiz.cpl” and press Enter to open up Programs and Features.
    Run dialog: appwiz.cpl
    Run dialog: appwiz.cpl
  2. Inside Programs and Features, scroll through the list of applications to locate Oracle VM VirtualBox. Once you see the entry, right-click on it and choose Uninstall. Then, follow the on-screen prompts to remove the software from your system.
    Uninstalling Oracle VM VirtualBox
    Uninstalling Oracle VM VirtualBox
  3. Once the software has been uninstalled, restart your machine. At the next startup, make sure that no 3rd party antivirus is running.
  4. Open File Explorer and navigate to the following location:
    C:\ Program Files \ Oracle \ VirtualBox \ drivers \ vboxdrv \ VBoxDrv.inf
  5. Once you get there, right-click on VBoxDRv.inf and choose Install, then click Yes at the UAC (User Account Control) prompt.
    Installing the VBoxDRV.inf (VirtualBox kernel driver) file
    Installing the VBoxDRV.inf (VirtualBox kernel driver) file
  6. Once you see “The operation completed successfully” prompt, click Ok and run the virtual machine again. It should open without the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error.
    Operation is completed succesfully
    The operation is completed successfully

Method 4: Installing Microsoft’s bug fix update (Windows 7 only)

As per various user reports, there is one Windows update that is confirmed to be causing the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error. As it turns out, the KB3004394 update will miss installing a .cat file which prevents VirtualBox from verifying the authenticity of several DDL files.

Note: If you are not on Windows 7, jump straight to Method 5.

Luckily, the fix for it is extremely simple since Microsoft has already released a hotfix for it. Follow the steps below to resolve the error (if it was caused by a bad update) on Windows 7:

  1. Visit this Microsoft official link (here) and download the hotfix for Windows 7 by clicking on Download the package now.
    Downloading Microsoft's hotfix
    Choosing the appropriate download package
  2. In the next screen, click the Download button to commence the download.
    Downloading the hotfix
    Downloading the hotfix
  3. Once the download is complete, open the update executable and follow the on-screen prompts to install it on your system. It will act as a removal tool, deleting the bad update altogether.
  4. Reboot your computer and open the virtual machine again at the next startup and see if you’re still encountering the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error. If you are, move over to the final method below.

Method 5: Starting the machine in the Headless mode (Temporary fix) 

If you’ve come this far without a result, there’s one fix that a lot of affected users have used to circumvent the “Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)” error. But it has one major downside – it’s only a temporary fix.

Several users have reported that the error doesn’t occur if they start the machine in Headless mode and then clicking on Show. Here’s a quick guide on how to do this:

  1. Open VM VirtualBox and click once to select the machine that is showing you the error message. Then, with the machine selected, click the arrow near the Start icon and choose Headless start.
    Click the drop-down menu associated with Start, then click on Headless Start
    Click the drop-down menu associated with Start, then click on Headless Start
  2. Wait 10-15 seconds, then click on Show to bring up the screen.
    Click on Show to bring up the virtual machine window
    Click on Show to bring up the virtual machine window

    That’s all there is to it. But keep in mind that you will have to repeat the procedure above every time you start up the virtual machine.

Kevin Arrows


Kevin is a dynamic and self-motivated information technology professional, with a Thorough knowledge of all facets pertaining to network infrastructure design, implementation and administration. Superior record of delivering simultaneous large-scale mission critical projects on time and under budget.

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Fix: Virtual machine has terminated unexpectedly during startup with exit code 1 (0x1)

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