Make sure you have checked the System Requirements section before attempting the installation.
In the %REP_HOME%\Rep Attack 11g XE directory, double click on the VirtualBox installer file called VirtualBox-<version>-Win.exe, and follow the instructions. You will need Administrator privilege on your computer to install VirtualBox.
The example shown here is installing VirtualBox 4.3.14 although version 4.3.12 is distributed with Rep Attack and works fine. The installation should only take a few minutes at most.
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Accept the default configuration and location. Click Next to continue. If you do change the location of program files from C:\Program Files\Oracle\VirtualBox\, you will need to edit the PATH environment variable that is set in the machine_setup.bat script.
Accept the default options and click Next to continue.
Click Yes to continue. Your network connections should be restored without interruption.
Click Install to start the installation.
The software files will be copied onto your machine. Click Next when complete.
When the installation has completed, click Finish and the VirtualBox Manager will start.
Check the Host-only Network Configuration
If you already had VirtualBox installed, check that you have a Host-only network configured on the host. If this is a fresh install of VirtualBox, check that the Host-only network adapter is configured as below.
Use the Oracle VM VirtualBox Manager GUI, Select File --> Preferences, then in the VirtualBox - Settings window, select Network. In the Network pane, select the Host-only Networks tab and check you have an entry named VirtualBox Host-Only Ethernet Adapter.If not, click the add host-only network button to add it.
Highlight the adapter and click the edit host-only network button to check its properties. In the Host-only Network Details window on the Adapter tab, check that the IPv4 Address setting is 192.168.56.1 and the IPv4 Network Mask is 255.255.255.0. The DHCP Server can be enabled or disabled. This configuration does not use the DHCP server.
Congratulations! you have successfully installed Oracle VirtualBox on Microsoft Windows.