since you have IDE drives you need to define via Jumper settings which is the Primary and which is the Secondary device on the cable.
there is a Jumper in the back of the drive which has three settings marked C S M
C = Cable Select
S = Slave
M = Master
If two drives are connected to one cable, there is two ways to configure them.
Either set the Jumper on both to C, or set one to M and the other to S.http://www.helpwithpcs.com/upgrading/install-cd-dvd/install-cd-writer-fig-1-2.jpg