Durring install process (the lilo confog part) It is aked to the user to add another OS. Before release 6.1 (6.0, 5.2, 5.1 etc..) it was possible to choose NT as alternative boot. NTFS partitions were recognised as HPFS partitions. With Red Hat 6.1 it isn't possible any more.
Assigned to dledford
Newer versions of Red Hat Linux provide this functionality again.