In order to run other operating systems in virtual machines alongside your main operating system, needs to integrate very tightly with your system. To do this it installs a driver module called vboxdrv into the system kernel. The kernel is the part of the operating system which controls your processor and physical hardware. Without this kernel module, you can still use to configure virtual machines, but they will not start.

Network drivers called vboxnetflt and vboxnetadp are also installed. They enable virtual machines to make more use of your computer's network capabilities and are needed for any virtual machine networking beyond the basic NAT mode.

Since distributing driver modules separately from the kernel is not something which Linux supports well, the install process creates the modules on the system where they will be used. This means that you may need to install some software packages from the distribution which are needed for the build process. Required packages may include the following:

• GNU compiler (GCC)

• GNU Make (make)

• Kernel header files

Also ensure that all system updates have been installed and that your system is running the most up-to-date kernel for the distribution.

The following list includes some details of the required files for some common distributions. Start by finding the version name of your kernel, using the command uname -r in a terminal. The list assumes that you have not changed too much from the original installation, in particular that you have not installed a different kernel type.

• With Debian and Ubuntu-based distributions, you must install the correct version of the linux-headers, usually whichever of linux-headers-generic, linux-headers-amd64, linux-headers-i686 or linux-headers-i686-pae best matches the kernel version name. Also, the linux-kbuild package if it exists. Basic Ubuntu releases should have the correct packages installed by default.

• On Fedora, Red Hat, Oracle Linux and many other RPM-based systems, the kernel version sometimes has a code of letters or a word close to the end of the version name. For example "uek" for the Oracle Unbreakable Enterprise Kernel or "default" or "desktop" for the standard kernels. In this case, the package name is kernel-uek-devel or equivalent. If there is no such code, it is usually kernel-devel.

• On some SUSE and openSUSE Linux versions, you may need to install the kernel-source and kernel-syms packages.

If you suspect that something has gone wrong with module installation, check that your system is set up as described above and try running the following command, as root:

rcvboxdrv setup