NTFSDOS were three kinds of programs by Winternals (later bought by Microsoft) for DOS that could handle NTFS formatted drives.

Programs

Basic

The first program was NTFSDOS - a freeware utility for DOS (NTFSDOS.EXE) that allows read-only access to NTFS formatted drives from a DOS environment.

Tools

The second program was NTFSDOS Tools - an add-on package for NTFSDOS that contains two commercial utilities for DOS - NTFSCopy and NTFSRen. The former (NTFSCOPY.EXE) could be used to overwrite corrupt files with fresh versions. The latter (NTFSREN.EXE) could be used to change the names of bad drivers so Windows could not load them.

Professional

The final program was NTFSDOS Professional - a whole commercial solution for handling read and write operations in NTFS from a DOS environment. It must be installed as a package for Microsoft Windows first. The downloaded version comes in demoware form. The user can only use the package in read-only mode in order to evaluate it.

Discontinuation

Winternals was acquired by Microsoft on July 18, 2006, which discontinued NTFSDOS.