Restore a Yocto ISO image on Windows Partition

So far, we have been able to restore the Yocto generated ISO image on the entire disk. I am looking for restoring the image only on a partition created by Windows. I need to have dual boot enabled with Windows 7 as well. Init-install script only helps me to restore the image on /dev/sda (disk) and not on /dev/sda3(partition). Any help will be appreciated.