NTBackup is the built-in backup tool introduced by Windows NT around 1997, it can be used to back up the vital files in Windows 2000/2003/XP, and easy to restore the backup in such operating system.
So if you want to restore them in other servers, like 2008,2012,2016,etc, it can be difficult. But you can get much help from https://www.backup-utility.com/articles/ntbackup-server-2012-7201.html