System boot issues

Hey there. So, I started putting together this old PC today, and for the most part, everything seems to be running fine. But here’s the kicker: whenever I try to install macOS, it just keeps telling me it can't find the operating system. At first, I figured my hard drive was shot, but I plugged it into my other machine and it reads it just fine as storage—still, no luck finding a system in the BIOS. I’ve checked all the settings, and they seem okay. My boot order is set to DVD first, then the drive with the macOS installer. I know the disc works because I used it to reinstall macOS for a buddy just the other day. I guess I'm just stuck. Any ideas? Please help.

Man, if you're lucky enough to actually get through this...
1 Does the BIOS even see your hard drive and DVD drive? If it does, jump to step 2
2 Are we talking about an old-school IDE cable here? If so, check your master/slave settings... if they look good, head to step 3
3 Is the DVD drive itself actually working? If it is, move on to 4, but if not, just call it quits right there
4 Do you have a floppy drive, a USB stick, or some other bootable device plugged in? If you do, unplug them—I can't help you if I don't have enough info to work with...........

So, here’s the deal. My hard drive shows up in the BIOS, but I’m getting a bit confused about the DVD drive. It used to always show the specific name of the drive, but now it just says "CD" or something similar. I have no clue why that changed. Anyway, I’ll try to explain what's happening. Since I’m working with an older machine, my hard drive doesn't use a SATA connection; it uses that old-school wide ribbon cable. I think that might be part of the issue. That cable has multiple connectors, so every time I switch which one I'm using, the system detects something different, but it only ever recognizes those two specific things. Here is what I'm seeing:
1. Boot failure
reboot and select proper boot device or insert boot media in selected boot device press any key when ready
That’s the first error. Then there's this second one:
2. An operating system wasn't found. Try disconnecting any drives that don't contain an operating system.

we've got everything squared away now...
you just gotta stick to the game plan...

mod, go ahead and lock this thread...

Alright, so your DVD drive isn't working for some reason—is that thing also running on a SATA connection? Are the disc and the optical drive actually tied to the same SATA cable?

So, here’s the deal. My DVD drive and HDD are on the same ribbon cable. The hard drive itself seems fine, but I can't get anything to boot from it. I sent over a screenshot of the error message I'm getting. The DVD drive works just fine when I try to read discs. I recently tried installing macOS on this new PC because my old one finally kicked the bucket and I've been stuck using a single DVD drive to get things moving.

Here’s how you clear the CMOS: kill the power, pop the battery out of the motherboard, hold down the power button for like 10 seconds, then put everything back together. Boot into the BIOS and just reset everything to factory defaults. From there, you can fix the master-slave settings and the boot order.

That should do the trick.

Look, right now I just need a DVD drive so I can get macOS installed. After that, I don't really have any use for it, I guess.

Hey man, you kind of gave me the gist of all that earlier, but what exactly do you mean by a motherboard battery? I mean, I know my way around a PC well enough to get the idea, but maybe you could walk me through it just a bit more clearly

hey, just pull this out

I guess you mean RAM, if I'm not mistaken??

Nah, looks more like some oversized watch battery, check out these pics

got a video too

I did exactly what you suggested, but now I'm stuck. How do I actually get back to the factory defaults? I need to reset everything to the master BIOS settings, but I'm working with an older version here.

Man, I caught that video you posted. I actually tried doing the same thing myself, but that PC in the clip? It’s a total relic. We're talking a Pentium 4, 2.66GHz, maybe 512 MB of RAM... stuff like that. Honestly, I think the BIOS on that machine is even older than the one shown in the video itself.

When you hit the BIOS, it’ll probably tell you to just stick with the defaults. Don't listen. Just go in there and fix the boot order: 1) DVD, 2) HDD... also, make sure that hard drive is set as the master. If it isn't, let me know which drive you're messing with.

Thanks, but since I’m stuck with just one monitor, I’ll have to hook it up to a different PC tower. Give me five minutes to get that sorted.

And another thing... when I'm hooking up a DVD drive and a hard drive to a single ribbon cable, is it actually possible to have them both sitting on one line? And about those ports on the cable—some of them are missing a pin or two while others look complete—which specific one should I be plugging both the DVD and the HDD into?

Shouldn't matter much, just watch the power supply... if you can, try putting each one on its own rail.

I mean, he really ought to know that there shouldn't be any issues here, considering we're just dealing with an old hard drive and a DVD

So, I tried doing it exactly the way you guys suggested, but I kept getting that same error message telling me to insert boot media. I ended up plugging the DVD drive into an extension cable because I was missing a pin, and then it just sat there saying "searching for boot" or something along those lines. The drive started making this really loud, aggressive whirring noise, and then—out of nowhere—it just completely cut out. And then, of course, it goes right back to that same prompt asking me to insert boot media again.