Promise Ultra66 PCI with SCSI Raid Controller

Hello experts,

I have an old Dell Poweredge 2400 with a single 40GB SCSI drive running WinAdvancedServer2K.  I am running out of space on that drive.  

I had a Promise Technology Ultra66 PCI card laying around here and found a great deal on a 300GB IDE drive.  So I'm trying to use this in my server.

Unfortunately, I'm an idiot when it comes to SCSI so it's not going easy for me.

I have the following SCSI devices installed (from system info):

Adaptec AIC-7880 PCI SCSI Controller
Dell PERC 2/Si RAID Controller
Promise Technology Inc. Ultra66 IDE Controller
Adaptec AHA-2940U2/U2W PCI SCSI Controller
D347PRT SCSI Controller

The IDE drive has not been formatted.  I attached it to the Ultra66 card right out of the box.

And finally, the symptoms.  

If I attach the IDE drive to one of the two IDE ports on the Ultra66 card, the computer boots as normal and I can see the Promise Technology card listed under SCSI devices in device manager.  Its status is listed as working correctly but I don't see the drive in computer management --> storage.

If I plug the IDE drive into the other IDE port on the Ultra66, I get a message before the OS loads saying something about reducing to Ultra33 because of a 40 pin ribbon cable and then it just goes to a blank screen and the OS doesn't load.

I'm assuming the second scenario is because the PC is trying to load an OS from the IDE drive.

Can you tell me step-by-step what I need to do to get this working (if it's even possible at all)?

Any help will be GREATLY appreciated.

Thanks!