Install VirtualBox for your Operating System on your host machine. Rep Attack RepAttack uses VirtualBox version 4.3.12 or greater. If you already have VirtualBox installed on your host system, check that it is at least version 4.3.12 as the virtual machines you will be running have this version of the Guest Additions installed on them. Upgrade your VirtualBox installation to at least this version if required.
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A copy of the installation media for VirtualBox is included with Rep AttackRepAttack. For Windows it's VirtualBox-<version>-Win.exe, and for Mac OS X it's VirtualBox-<version>-OSX.dmg. VirtualBox for Linux is distribution specific and can be downloaded for your version of Linux from the Download VirtualBox for Linux Hosts page.
If a newer version of VirtualBox is available, you can download that if you want from the Download VirtualBox page but the version included with Rep Attack RepAttack will work fine.
Follow the installation instructions for your host operating system below.
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