Unless you really, REALLY know what you're doing, don't go ANYWHERE near an NTFS volume with a sector editor.
NTFS is a proper filing system, with all sorts of things you didn't know it had, like streams, metadata journalling, per-file compression, encryption, hidden files and all sorts of other horrors. It's not terribly well documented, natch.
It's not FAT16 with long filenames and permissions, that's fer shure.
Fix the problem with the tools at hand - that's CHKDSK, basically.
If it were me? Well, firstly I'd be seriously fascinated as to how such a file could come into existence and some serious poring over the system logs would be done. (I had a brief play with this - I *could not* create a file anywhere in my filesystems called "COM1", either from an application or the command line).
Then I'd back up the volume with the exception of that one file, format it, and restore.