The source code of the kernel of Windows server 2003 and Windows XP Pro x64 was available to universities for education purposes. Someone leaked the code on internet years ago which is now everywhere on github (search WRK-v1.2). The code doesn't include the ntfs module.
Actually given the horror stories that have been told about the windows source code over the years, I'd be very, very surprised if there wasn't 20 year old code in a lot of places.
Hell there's still 20 year old code running in the Linux kernel
I'd actually be surprised if there weren't quite a bit of it still in the kernel.