It is sometimes convenient to be able to run Tails without having to restart your computer every time. This is possible using [[!wikipedia Virtual_machine desc="virtual machines"]].
With virtual machines, it is possible to run Tails inside a *host* operating system (Linux, Windows, or macOS). A virtual machine emulates a real computer and its operating system, called a *guest*, which appears in a window on the *host* operating system.
When running Tails in a virtual machine, you can use most features of Tails from your usual operating system, andyou can use both Tailsand your usual operating system in parallel, without the need to restart the computer.
<p>Running Tails inside a virtual machine has various security implications. Depending on the host operating system and your security needs, running Tails in a virtual machine might be dangerous.</p>
Traces of your Tails session are likely to be left on the local hard disk. For example, host operating systems usually use swapping (or *paging*) which copies part of the RAM to the hard disk.
<p>The Tails virtual machine does not modify the behaviour of the host operating system and the network traffic of the host is not anonymized. The MAC address of the computer is not modified by the [[MAC address anonymization|first_steps/welcome_screen/mac_spoofing]] feature of Tails when run in a virtual machine.</p>
To run Tails inside a virtual machine, you need to have virtualization software installed on the host operating system.Different virtualization software exists for Linux, Windows, and macOS.
<p>We only mention Free Software, because we believe that it is a necessary condition to be trustworthy. Proprietary virtualization software exist, such as <i>VMWare</i>, but is not listed here on purpose.</p>
<p>We are not recommending <i>VirtualBox</i> anymore because only basic functionalities of Tails work in <i>VirtualBox</i>, for example, the display size is limited to 800×600 pixels.</p>
