VirtualBox allows you to create a virtual machine capable of running multiple operating systems without the need for dual booting or hardware configuration. The installation process for VirtualBox is fairly straightforward, with most of the time spent installing the desired operating system. See Step 1 below for instructions on how to set up VirtualBox and an operating system.
Steps
Install VirtualBox

Download VirtualBox. You can get Oracle's VirtualBox for free from the developer's website. Be sure to download the version that's compatible with your operating system.
- There are many options for Linux systems. Choose the appropriate package for your distribution or select the "All distributions" option if your specific Linux version isn't listed.

Install VirtualBox. If you're using Windows, simply double-click the installer file and follow the prompts. On a Mac, open the downloaded DMG file and drag the VirtualBox application into the Applications folder.
- For the Windows installation, it’s best to leave the default settings unchanged.

Launch the program. VirtualBox allows you to manage multiple virtual machines and easily create new ones. You can start VirtualBox either directly from the installation program or by clicking its icon on your desktop.
Create a Virtual Machine

Prepare installation media. When creating a virtual machine, you'll need to install an operating system just like on a physical machine. This means you will need an installation disk or ISO file to proceed.
- If you have an ISO file for the operating system, you can either burn it to a blank DVD or install directly from the ISO file.

Click the 'New' button. This action will open the wizard that guides you through the process of setting up a new virtual machine.

Identify the Operating System. In the first screen of the setup wizard, you will be asked to name your virtual machine and select the operating system you want to install. Choose the operating system from the Type menu and then pick the corresponding version from the Version menu.
- For example, to install Windows 7, select "Microsoft Windows" in the Type menu and then choose "Windows 7" from the Version menu.
- If you're installing the 64-bit version of the operating system, make sure to choose the 64-bit option in the Version menu.

Set up RAM. You need to specify the amount of RAM allocated to the virtual machine. VirtualBox will automatically select the minimum required for the operating system, but you can adjust it as you wish.
- You can choose a RAM amount similar to what would be used for a standard OS installation.
- Avoid selecting the maximum amount as it might leave no free space for the regular OS to function while the virtual machine is running.

Create a Virtual Hard Disk. The virtual machine requires a virtual hard disk to install the operating system and programs. This virtual hard disk is created in free space on the host machine. VirtualBox will set an appropriate size based on the operating system, though you can adjust it yourself.
- Ensure that the virtual hard disk has enough space to install the operating system. Check the system requirements of the OS to determine the minimum disk space needed.
- Remember, any programs installed will use the virtual hard disk’s memory, so plan accordingly.
- The most common virtual hard disk format is VDI (VirtualBox Disk Image).

Start the Operating System Installation. After configuring the virtual machine, the wizard will close and you will be taken to VirtualBox’s main screen. Double-click the new machine in the left-hand menu to begin the initial boot.
- A new installation wizard will appear to guide you through the operating system installation process.
- If you're installing from a disk, insert the disk into your computer and select "Host drive" from the menu, then choose the corresponding drive name from the dropdown list.
- If you're installing from an image file, click the folder icon to browse your computer and start the installation.

Install the Operating System. After selecting your installation method, the process will begin. The installation steps are similar to those of installing an operating system on a regular computer. Refer to the specific guides for the operating system you're using for more details:
- Windows 8
- Windows 7
- Windows Vista
- Windows XP
- OS X
- Linux Mint
- Ubuntu Linux
Using Virtual Machine

Start the virtual machine. After installing the operating system, your virtual machine is ready to use. To start it, double-click on the virtual machine listed in the left menu of VirtualBox's main screen. The virtual machine will boot up and load the operating system you just installed.
- The virtual machine operates in its own window. Regardless of which window is in focus, any keystrokes or mouse clicks will only affect the virtual machine, not the host machine.
- You can create a desktop shortcut by right-clicking the virtual machine in the VirtualBox window and selecting "Create Shortcut on Desktop".

Shut down the virtual machine. You have a few options for shutting down the virtual machine, and each option has a different effect. When you click the "X" at the top right of the screen, you'll see several options:
- Save the machine state - This option allows you to save the virtual machine's current state. Programs will remain in their current state, and everything will be restored when you start the machine again.
- Send the shutdown signal - This option simulates pressing the power button on the host computer, forcing the virtual machine to shut down.
- Power off the machine - This option cuts the power to the virtual machine, just like turning off the power supply. Any unsaved data will be lost.

Take a snapshot of the virtual machine. VirtualBox lets you capture the exact state of the virtual machine and return to that state at any time. This is extremely useful when testing software or reconfiguring the system.
- To take a snapshot, click on the "Machine" menu and select "Take Snapshot". The snapshot will appear in the list of virtual machines on the left side of the VirtualBox menu.
- You can restore a snapshot by right-clicking the snapshot and selecting "Restore". Any changes made to the virtual hard drive after the snapshot was taken will be undone when the snapshot is restored.
