I have tried 2 different harddisk, connected them with a 80 type cable, (the
disk runs when I turn on computer) but upon startup the computer does not
see this disk.

I am using winxp, sp 2 and AMD dual core CPU.AMD 64

I have tried to plug the second disk to the top of the cable and also to the
middle of the cable. It makes no disference.

I also set this second disk to Slave.

Why would it not work?