Installation(Dual Boot)

I have 98SE on my T20 ibm thinkpad with a hard drive with 4 5gig partitions. I am trying to install windows 2000 Professional as a dual boot. However, when I attempt to install Windows 2000 it only show my C drive as one big 20gig drive instead of drives c,d,e,f since I must load 2000 on d,e, or f. Need some specific instructions please.