. Img file is that when you are running the following from the command line only.
Img files only work when you have the following from the command line.
Once you have the. Img file just run the following from command line:.
VBoxManage convertfromraw -format VDI [filename].img [filename].vdi
Depending on the size of .img file it might take a little while as for my desktop machine it took like around 5 minutes for converting a 4GB img file to vdi format. Once its all done just add the VDI file as another disk, attach it to a VM in VirtualBox… start the VM and you just got it all working