Cannot Find Out the Hard Drive In Win98

Would anyone tell me why my 2GB
harddisk cannot be detected by Win98.
However, it can be identified by my
motherboard in bios?

I have changed the jumper to slave
because I have a new 30GB harddisk. I
use the first primary IDE to connect two
harddisk, one is 30GB for master and
other one is 2GB for slave. Then I use
second primary IDE to connect a CD-
ROM.
Thank You.