Adding to what Journeyman Geek said.
It gets recommended (at times) to put the CD in as slave. It does sound like Joshua covered all the things, some drives/controllers will simply not work with a CableSelect method/setting. Some worked better using CS methods.
Some drives have "master" "slave" and a 3rd jumper setting "Master with slave" . Those drives caused me problems, because of the 3rd setting, when combining with the CD (because it is master expecting a slave to exist, testing alone vrses testing with a second item is different).
The jumper info was not always correct. Getting onto the hard drive manufactures site , and checking/comparing jumper config for that specific drive was important.
When trying to get it to boot to an OS, like a windows OS, there has to be an MBR for the system on it.
The boot files have to be there on the disk.
The error you get is most common for the boot files, MBR not being set-up, or the disk not being in boot order, or not being seen.
I had one disk with a MBR problem that did not clear easily. I don't know enough about how all that works , but it was not a disk fail problem , although it acts like one. And the standard methods for resetting the MBR did not work.
You have an OS on it, but did not describe If you were putting it on, or moved it from somewhere, or if it is a working image ?
I would Back up a bit in a situation like this, and Insure that the cables and jumpers are correct, then Not boot into the disk operating system. I would try and observe the disk Via a different disk first. You did not describe using any "other" boot thing like boot CDs or Boot flash drive, or even floppy, to look at it from the outside.
Back even further in Diagnosis, when doing the PATA thing , the area of the BIOS that shows the existence of the hardware was useful. If it did not show up in the hard disk section, It was often some hardware issues I had not completed correct. Jumpers, cables, slot used.
Other notes: when it boots or your trying to get into it from another boot, being slow can be a cable issue, or a disk issue, , plus many other things, but those 2 would be more common.
if you need more information, add more information or testing info to your question?