資料參考：http://blog.carlossanchez.eu/2011/08/01/migrating-windows-7-from-vmware-fusion-to-virtualbox/

Step by step instructions

To move the Windows 7 image to VirtualBox 4.1 just needed to

1. Uninstall the VMWare tools and shutdown windows
2. Copy the disk files from VMWare image to a new folder
   1. In Documents/Virtual Machines right click on the image, Show package contents
   2. Copy all *.vmdk files to a new folder
3. Create a new VirtualBox machine with the same characteristics
   1. Make sure you choose Windows 7 64 bits if that’s what you used
   2. On Virtual Hard Disk, choose the main vmdk file you copied in previous step (although you’ll need to change the default storage config later)
   3. Customize created VM settings:
      1. General: Windows 7 64 bits
      2. System/Motherboard: set the same amount of base memory as the VMWare one
      3. System/Motherboard: Enable IO APIC
      4. Storage: By default VirtualBox adds it to SATA controller but you have to remove the SATA controller, and use IDE PIIX4 without host I/O cache, attaching vmdk to primary master IDE, leave CD/DVD drive
4. Boot the VirtualBox VM and follow any prompt to restart Windows to install new devices
5. On the VirtualBox Devices menu, click on install guest additions