Use when converting the image of a disk, containing Windows, and the resulting virtual disk is supposed to be bootable. With this key, the program will add drivers, necessary for the virtual machine type selected with the vm_type key, to the resulting virtual disk. If the image was taken from a virtual machine of the same type, normally the key is not needed.
Drivers for the virtual machine reside in the storage, defined by the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Acronis\UniversalRestore\DriversPackPath. In case the storage has been moved, please change the key or use the command ur_path:[path].