??? what fo you mean by d: redhat? If it's a ext3 partition it's not visible under win98!
Under linux, you make a lilo/grub diskette to boot from a given partition on your hd, if you messed up with MBR.
You can write a real bootable dos disk only if you previously copied a diskette to a file with
dd if=/dev/fd0 of=/root/winbootdisk.img bs=1024 count=1600
PS if you're in trouble look here:
http://www.drd.dyndns.org/fr_index.html?/disks.html
you may be able to use these under wine
