To set up Virtualbox you will need a full version of Microsoft Windows.

Download preferred version of Windows and create a bootable medium for the downloaded .iso file. Rufus (https://rufus.akeo.ie/)is a good, easy, and free method of creating bootable USB drives.

Download Virtualbox at https://www.virtualbox.org/wiki/Downloads

• Select VirtualBox 5.0.16 for OS X hosts  amd64

Once downloaded, run the .dmg file. Install the package and then run the installed application from the Applications folder.

• Select ‘New’
  

• Name operating system, select version
   

• Memory Size
• First determine the amount of RAM available to Mac. Select “About this Mac” from the Apple icon at top left of screen. Never allocate more RAM than is available to MAC (red and green bars help determine the amount of RAM accessible). 2GB is suggested for Windows 7
   

• Hard Disk
• Create a virtual hard disk now
  
• VDI (VirtualBox Disk Image)
  
• Storage on physical hard disk
• Dynamically allocated (recommended)
  
• Only uses space on hard drive as it fills up to a fixed maximum that is set by user.
• Fixed size
• Allocates a file size to a set amount. May take longer to set up, but us often faster to use.
  

• Once the Virtual Disk is created, select Settings
• General
• Advanced
• Shared Clipboard: Enabled
• Shared Drag ‘n’ Drop: Enabled
  

• Encryption
• Optional
• System
• Motherboard
• Boot Order: Enable/Disable relevant drives
  

• Processor
• Processor(s): Determined by the specific processor the computer has. The green bar can be used to determine what is available to use.
• Execution cap: The max performance of drives. 100% is fine, but can be set at any desired level in green range.
  

• Display
• Video Memory: Windows uses a lot of video memory, it is suggested to max the available memory.
• Acceleration: Enable 2D and 3D acceleration
  

• Network
• Adapter 1
• Attached to: Bridged Adapter (tells virtual machine to create its own IP address)
• Name: Select primary way computer accesses network (Ethernet/WiFi)
• Adapter 2
• Attached to: Bridged Adapter (tells virtual machine to create its own IP address)
• Name: Select secondary way computer accesses network (Ethernet/WiFi)
• Shared Folders
• The folder that is sharable between the virtual machine and the host computer
• Add/remove desired folders
  

• Select ‘OK’ to save settings
• Select ‘Start’ to run Virtual Machine
• Insert bootable medium (CD, USB) with Windows operating system
• Select ‘Machine” from top menu bar, then select ‘Reset’
• Install Windows as normal

For any additional questions or troubleshooting tips, please visit the VirtualBox website (https://www.virtualbox.org/wiki/VirtualBox) and consult to their forums and FAQ under Community link.