here we are going to convert .vdi files to .raw .
Set your VirtualBox Path in Environment Variables (Path=E:\Oracle\VirtualBox\VirtualBox.exe)
a. Go to a cmd prompt and navigate to the VirtualBox folder (typically E:\VM\erpnext) which one we have already in vdi format .
b. Execute the following command:
vboxmanage.exe internalcommands converttoraw “E:\VM\erpnext\erpnext.vdi” “D:\erpnext.raw”