Virtualbox does actually support importing VHD file, unfortunately this is seulement for VHD's created avec Virtual PC, pas Hyper-V, qui adds certains additional information to le VHD. Some people have successfully got VHD Vm's to boot by ensuring le VM in Virtualbox uses an IDE plutôt than SATA controller.
Je suis pas aware of anyway to convert VHD's straight into virtual box, however you can convert VHD files into VMWare VMDK files (using tools like Starwind V2V) qui Virtualbox is alors able to use.
