boot – Customised .ISO installation in VirtualBox

I have created customized image (.iso) file in ubuntu using SYSTEMBACK Tool and trying to install it in VirtalBox but unable to do so. My intention is to install the image in VirtualBox and then after installation, when I run VM in VirtualBox, it should automatically load OS without even referring to .iso/ .vdi file again. In my case, since the image is not getting installed even after using “System Install” option at bootup, .iso reference is always necessary when I switch On the VM everytime. So kindly let me know the correct procedure to install customized .Iso in VirtualBox so that everytime OS loads up without depending on image file.