Apologies for the mis-direction by ZeroCool, but this forum supports Ghost Solution Suite, whereas you are using the retail Norton Ghost product, which is based on a different technology to GSS. If you look at the sticky posting at the top of this forum, it will direct you to the Norton Community where the retail product is supported. Unfortunately it is hosted outside "Connect" so I cannot transfer your thread, and you will have to repost.
Having a machine joined to a domain does not in any away affect your ability to log on user local accounts, by specifying the machine name in the domain field and entering local username and password. Equally, you can log on either as local administrator or as domain administrator and achieve the required level of administrator privilege for running Ghost. What I would point out, however, is that Ghost is intended as an IMAGING solution and is not designed for making backups in the conventional sense. Of course if you record an entire hard disk image, that will be a backup of both operating system and data, but usually, a backup process focuses on recording a copy of user data and nothing else.
Where do you intend to backup your information to? It is not clear whether you have space on the server and want to backup to there, in which case the Backup Exec software would be a much better choice. If you don't have server space for this purpose, the cheapest solution would probably be to source an external USB hard disk from a vendor such as Western Digital. These external hard disks usually come with a comprehensive backup software package that can handle all your data backup requirements easily.