Version 50 (modified by frank, 15 years ago) (diff)


Frequently Asked Questions for end users (User FAQ)

Here you can find common questions, frequently asked on the VirtualBox mailing lists and IRC channel, along with their answers. Please consult this list every time you run into a problem that is not described in the User Manual.

Note that we update the User Manual on a regular basis, and information that first shows up on this page is moved to the User Manual regularly. As a result, please do check the User Manual also, especially the "Troubleshooting" section.

Also make sure to check whether you are running the latest version of VirtualBox.

This particular FAQ is for end-user issues only; you may want to look at the Developer FAQ and Licensing FAQ for additional topics.


  • Starting with 1.4.0, VirtualBox now supports 64-bit Linux hosts. 64-bit Windows hosts are not yet supported; this is being worked on. Also, 64-bit guest operating systems are generally not supported.
  • Sometimes VirtualBox fails to start with a message on the lines of
    Failed to create VirtualBox COM object
     Callee RC: 0x80470007
    This usually means that the VirtualBox COM server was unable to start up, and is often a sign of problems in your installation of VirtualBox. In many cases this problem can be solved simply by reinstalling VirtualBox. Reinstalling will simply set up the VirtualBox program files again, and will not affect any virtual machines which you have created.

If this does not help, and you wish to investigate the problem further yourself, try starting the VirtualBox COM server (the program VBoxSVC in the VirtualBox program folder) from a command prompt or a DOS box. You may be able to see what is going wrong from error messages when the server starts.

Please do not open bug reports when you get this error before you have tried the other available support channels ( forums, mailing lists and IRC).

Linux hosts

  • Tickless Linux timer: VirtualBox currently does not work well on Linux kernels which where configured with tickless timer support (CONFIG_NO_HZ). We are investigating the problem but in the meantime you should disable the tickless timer by disabling the config option or by adding 'nohz=off' to the Linux kernel command line.
  • If you get a message saying "VirtualBox kernel driver not accessible, permission problem" when starting VirtualBox right after installation, make sure that your user account is listed in the vboxusers group. The installation takes care creating that group, but you will need to manually add all users to it that should be allowed to run VirtualBox. As root, for each such user, run usermod -G vboxusers -a <userid>. If any of the affected users are currently logged in, they need to log out for the changes to take effect. In case any user already attempted to start VirtualBox before logging out (which launches the VBoxSVC service process with incorrect permissions), that user additionally needs to run VirtualBox shutdown from the command line to terminate the service. This solves the permission problems. (Alternatively, a reboot will help as well.)
  • If the kernel module refuses to load with a message saying "Error inserting vboxdrv: Invalid argument", check (as root) the output of the "dmesg" command, and see "Troubleshooting" -> "Linux hosts" in the User Manual for solutions.
  • Host interface networking with dynamic TAP interfaces does not work with VirtualBox versions 1.3.8 and earlier on Linux kernels 2.6.18 and newer. Please update to VirtualBox version 1.4.0, where this was fixed.
  • If USB doesn't work, check your usbfs permissions. See "Troubleshooting" -> "Linux hosts" in the User Manual for a solution.
  • When installing from a Debian/Ubuntu package, the installation script will ask the user to accept the VirtualBox Personal Use and Evaluation License (PUEL) one time. Accepting this license is necessary to install this package. Some Debian/Ubuntu systems have selected the non-interactive debconf frontend. The license dialog can not be displayed on these systems and the package will refuse to install itself. The recommended debconf frontend is either GNOME or KDE which can be selected using
    dpkg-reconfigure debconf
    executed as root. Some systems use the dialog frontend which is acceptable as well. Note that to accept the license with this frontend, the user has to use the tabulator key to switch to 'Yes'. Clicking with mouse will not work. This is a limitation of this specific debconf frontend.
  • Debian/Ubuntu 1.3.2 packages: If the installation of the VirtualBox_*.deb package was not successful because the compilation of the kernel module fails, it might not be possible to remove the package nor to install other packages as the pre-remove (prerm) script of the package (which is executed prior to package removing or upgrading) aborts with an error "(Kernel module not found)!". In that case do the following:
    • Edit /etc/init.d/virtualbox and change line 129 from 'exit 1' to 'exit 0'
    • Reinstall the VirtualBox package by 'dpkg -i <the VirtualBox package for your distribution>'. An installation failure of this package is expected.
    • Edit /var/lib/dpkg/info/virtualbox.postinst and change line 39 from 'exit 1' to 'exit 0'
    • Execute 'dpkg --configure --pending'
    • The package should now be installed successfully. However, the kernel module is still not compiled. Before you will be able to execute VirtualBox you have to create a kernel module for your current kernel, as described in the User Manual (see our Downloads section).

This shouldn't be necessary anymore for newer Debian packages.

Windows hosts

  • Currently, VirtualBox only works if you have administrator rights. We are working on supporting regular user accounts.
  • Windows Vista hosts might show an error about a COM server not being accessible. This is a problem of our installation routine which we have not figured out yet. To fix the problem, open a command prompt shell and enter:
    cd \Programs\InnoTek VirtualBox
    VBoxSVC.exe /ReRegServer
    regsvr32.exe VBoxC.dll
  • If a VirtualBox version before 1.4.0 messes up your USB stack on Windows and you can no longer work with your USB devices, try removing VBoxUSBFlt from LowerFilters of the following registry key:
    The problem was fixed with VirtualBox 1.4.0.

Windows Vista guests

  • There is no networking in Windows Vista guests initially because, unfortunately, with Vista, Microsoft dropped driver support for the virtual AMD PCnet card that we are providing. See "Troubleshooting" -> "Windows guests" in the User Manual for a solution. The VirtualBox Guest Additions of version 1.4.0 contain the AMD PCnet driver.

High CPU load while running Windows 98

  • That is a problem of Win98. This guest is not executing the 'hlt' instruction when idle. Download and install rain20 from

Linux guests

  • The VirtualBox 1.4.0 Guest Additions do not work out of the box with Fedora 7 guests. Before you install the Additions, add the following lines to your Fedora 7 guest's /etc/X11/xorg.conf file:
    Section "ServerFlags"
            Option      "Xinerama" "true"
  • Mouse in PCLinuxOS: Look at /etc/X11/xorg.conf for the ServerLayout section and comment out the following line:
    InputDevice "Mouse2" "SendCoreEvents"

After restarting the X server, the mouse should work fine.
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