This blog post will explain how to grant VirtualBox access to a physical drive on the host machine. Open a command prompt with administrator privileges and navigate to the folder that contains the VirtualBox executables. Type the command below to get a list of all physical drives.

VBoxManage list hostdrives

The VBoxManage command listed below will be used to create a VirtualBox hard disk image file that points to the specified host drive. That image file will have to be loaded in VirtualBox for it to be able to use the host drive with a virtual machine. VirtualBox has to be loaded with administrator privileges to have access to a physical drive. The # in \\.\PhysicalDrive# has to be replaced with a number.

VBoxManage internalcommands createrawvmdk -filename c:\sdcard.vmdk -rawdisk \\.\PhysicalDrive#