If you are DOS booting modern hardware, you will not be able to read the hard disk as DOS cannot access SATA devices. So you either need to check if the bios offers an IDE/ATA compatibility mode to allow old programs like DOS to see the hard disk, or you need to use WinPE.
You also need to note that Windows 7 consists of two partitions - one of around 100Mb and the second comprising the rest of the drive (or whatever portion is allocated to the C:\ drive). Both partitions are required for Win 7 to boot.
Also, make sure you have build 11.5.1.2266 of Ghost.