Some OSes expect certain key combinations to initiate certain procedures. The key combinations that you type into a VM might target the host OS, the software, or the guest OS. The recipient of these keypresses depends on a number of factors, including the key combination itself.

• Host OSes reserve certain key combinations for themselves. For example, you cannot use the Ctrl+Alt+Delete combination to reboot the guest OS in your VM, because this key combination is reserved by the host OS. Even though both Windows and Linux OSes can intercept this key combination, the host OS is rebooted automatically.

  On Linux and Oracle Solaris hosts, which use the X Window System, the key combination Ctrl+Alt+Backspace normally resets the X server and restarts the entire graphical user interface. As the X server intercepts this combination, pressing it will usually restart your host graphical user interface and kill all running programs, including , in the process.

  On Linux hosts supporting virtual terminals, the key combination Ctrl+Alt+Fx, where Fx is one of the function keys from F1 to F12, normally enables you to switch between virtual terminals. As with Ctrl+Alt+Delete, these combinations are intercepted by the host OS and therefore always switch terminals on the host.

  If, instead, you want to send these key combinations to the guest OS in the virtual machine, you will need to use one of the following methods:

  • Use the items in the Input, Keyboard menu of the virtual machine window. This menu includes the settings Insert Ctrl+Alt+Delete and Insert Ctrl+Alt+Backspace. However, the latter setting affects only Linux guests or Oracle Solaris guests.

    This menu also includes an option for inserting the Host key combination.

  • Use special key combinations with the Host key, which is normally the right Control key. then translates the following key combinations for the VM:

    • Host key + Del sends Ctrl+Alt+Del to reboot the guest OS.

    • Host key + Backspace sends Ctrl+Alt+Backspace to restart the graphical user interface of a Linux or Oracle Solaris guest.

    • Host key + Function key. For example, use this key combination to simulate Ctrl+Alt+Fx to switch between virtual terminals in a Linux guest.

• For some other keyboard combinations such as Alt+Tab to switch between open windows, enables you to configure whether these combinations will affect the host or the guest, if a virtual machine currently has the focus. This is a global setting for all virtual machines and can be found under File, Preferences, Input.

• A soft keyboard can be used to input key combinations in the guest. See .