I do have a dual boot Windows 98/2000 computer with a DAT tape drive on it. So far, I was unable to find a software able to replicate tape managemnt functions available in old Seagate Backup Exec built in Windows 98.
The old Backup Exec is able to append new backups to an existing tape and continue on another tape, if there is not enough space. When restoring, it is necesary to insert just the tapes with particular backup set. So, it is possible to create an endless chain of tapes.
With the Windows 2000 built in tape backup it is necesary to create multi tape backup sets. While restoring it is necesary to insert all the tapes beginning at the first one. So, if the particular files are located on the last tape, it is necesary to insert all tapes from the set. If the backup set is appended with another set of files, all the tapes have to be inserted while restoring the appended files. So, after appending a few files to 20 tape backup set, it is necesary to use all 20 previous tapes while restoring the appended files.
I found quite a few backup applications, but almost all of them do need windows XP or better. So, there was no point in testing them.