problems detecting new hardware

i have 2 hard drives 1 of which has windows 98 that i have
set up as a slave, the other has xp which i have set up as
master. my computer detects both drives on startup but
when i go into my computer it shows only the drive with
xp. the 1 with 98 does not show up in my computer why will
it not detect my hardware ? p.s the drives were
independant each with the seperate op system installed
without the other drive present does this make a
difference now i am trying to intergrate the 2 drives
together with xp as the master op system when 98 was
installed on 1 of the drives?