What's Windows NT????.....
seriously, that is some fossil. I guess it does not use NTFS filessystem, which Linux tools WILL see. You might try QTParted.
If you do fdisk -l, what does it say is in the place where you think NT should be? e.g. Does it see empty space?
Off-topic: I could never muster enough of a death wish to deal with NT--Win 2K is bad enough.