NTLDR controls dual-boot

Boot from the GRUB floppy.

Setup GRUB into the boot sector of the Linux partition, say /dev/hda1

   grub>root (hd0,0)
   grub> setup (hd0,0)

Boot into Linux. Copy image of the Linux boot sector onto floppy

dd if=/dev/hda1 of=linux.bin bs=512 count=1
mcopy linux.bin a:

Reboot into Windows; start command prompt;

cd C:
copy a:\linux.bin .

Edit boot.ini and add another line:

c:\linux.bin="Linux Debian 3.1"