Sorry but my advice is to never use NTBACKUP. It was dated in 2000 and now outdated to the extreme. Posts and complaints about file loss and restore problems are commonplace.

If you didn't grasp that consider NTBACKUP was supplied because folk were using that in Windows 2000 which was inherited from Windows NT which is to say "dang, that's old stuff." And it was not that great back then.

You're not way off. It's a very old program that was supplied just so folk could migrate from NT and 2000 over 10 years ago.

Use anything else.