So far you haven’t uploaded a picture of the Bios. Have you been in the Bios yet?
Don't let the computer think for itself ..It's an idiot. Stop letting it auto configure IDE. ..Get into Bios.
Try this, but first note this.
IDE/Pata cables usually have 2 connectors on. The middle one is always the Slave. The end one is always the Master. If it has a blue connector ..that is for the motherboard.
Set your hard drive to master (IE you need to put that connector on the middle pins) stick it on end connector. Don’t put anything else on the cable such as a second drive or CD/DVD drive.
Is there a second IDE/PATA cable connected to something?? Remove it for the moment.
For most computers or motherboards one presses delete to get into the Bios. For Dell it is usually F2
Do this ..
Turn computer off. Start computer while angrily and frantically thrashing your pinky-finger up and down on the F2 key while shouting go into the Bios you Bas__ard.
Once in Bios, unless by this time you have thrown computer out of window .. Go to Boot options ..select your WD drive as first Boot option.
If still no joy, try Cable Select – end pins. Reboot.
If still no joy …..Do you have a valid operating system on the drive?