okay using terms that arent OS specific would help ... "c" and "d" mean nothing in linux. describing your partition table better than "c" and "d" will help... but in the end, i think you'll just want to go without win98 ... seeing has how it's been "deprecated" since 2003. but if you installed linux on your computer last... you'll have boot loader problems if you install windows over it. the ms bootloader sucks. i think it would be easier to do this:
1. format all of your harddrives so all you have is blank space.
2. install windows 98 on one harddrive/partition
3. install windows XP (it will install a lame *** boot loader that is trash if you ever use grub)
4. install linux (will install grub if you picked a distro that doesnt suck (I.E. www.debian.org www.slackware.com www.ubuntulinux.org
what do you need windows 98 for anyway?