F5F Stay Refreshed Hardware Desktop What's going wrong when I try to start my computer? The Windows operating system isn't showing up.

What's going wrong when I try to start my computer? The Windows operating system isn't showing up.

What's going wrong when I try to start my computer? The Windows operating system isn't showing up.

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Tjeard_
Member
179
03-21-2026, 08:39 PM
#1
Hi, My PC has an ASRock X570 Taichi motherboard with an AMD Ryzen 7 3700X CPU. It's been working great for years but a few days ago I let it do a Windows update (I didn't check what it was) and shut it down. Since then, it won't start up. The computer shows "Windows operating system not found" when trying to turn on.

I have two hard drives in my PC: one 1 TB M.2 SSD and another 1 TB drive. My main boot drive is the 1 TB M.2 SSD. I also have a 6TB HDD and a DVD drive. All these devices show up in the BIOS, but they don't show up when it tries to start or load Windows. So both drives can't be used to boot from them or install fresh Windows on them.

Here are some pictures of the BIOS: https://ibb.co/39kBL614 https://ibb.co/d0TqSbkC https://ibb.co/HfWxgHvZ It seems like because both drives are involved, it's more likely to be a software problem inside the BIOS or MBR rather than a hardware failure. This is because two drives dying at once is unlikely and they still show up in the BIOS.

The PC hasn't been moved but even so I checked every plug and everything else looks secure. Thanks for any advice. Kind regards Lee
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Tjeard_
03-21-2026, 08:39 PM #1

Hi, My PC has an ASRock X570 Taichi motherboard with an AMD Ryzen 7 3700X CPU. It's been working great for years but a few days ago I let it do a Windows update (I didn't check what it was) and shut it down. Since then, it won't start up. The computer shows "Windows operating system not found" when trying to turn on.

I have two hard drives in my PC: one 1 TB M.2 SSD and another 1 TB drive. My main boot drive is the 1 TB M.2 SSD. I also have a 6TB HDD and a DVD drive. All these devices show up in the BIOS, but they don't show up when it tries to start or load Windows. So both drives can't be used to boot from them or install fresh Windows on them.

Here are some pictures of the BIOS: https://ibb.co/39kBL614 https://ibb.co/d0TqSbkC https://ibb.co/HfWxgHvZ It seems like because both drives are involved, it's more likely to be a software problem inside the BIOS or MBR rather than a hardware failure. This is because two drives dying at once is unlikely and they still show up in the BIOS.

The PC hasn't been moved but even so I checked every plug and everything else looks secure. Thanks for any advice. Kind regards Lee

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Ranger6800
Member
241
03-22-2026, 03:15 AM
#2
Hello everyone! If CSM (Compatibility Support Module) is turned on in your BIOS, please turn it off and check if your hard drives show up in the boot list. You need to update your BIOS first. I suggest flashing it to the newest version and then clearing your memory. Another idea? Take out all hard drives except the one that has your operating system.
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Ranger6800
03-22-2026, 03:15 AM #2

Hello everyone! If CSM (Compatibility Support Module) is turned on in your BIOS, please turn it off and check if your hard drives show up in the boot list. You need to update your BIOS first. I suggest flashing it to the newest version and then clearing your memory. Another idea? Take out all hard drives except the one that has your operating system.

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Tomcastle88
Member
149
03-22-2026, 08:28 AM
#3
Hey, thanks so much for getting back to me. That was really helpful. I followed your advice and tried all the bootrepair options that came with Windows. I also looked at a few other steps but haven't been able to figure out how to remove just one drive while keeping the rest connected yet. The main problem is my C: drive, which isn't actually labeled "C:" anymore; it's showing up as F:. I've tried everything else I can think of and I'm really stuck on what to do next. I guess a full reinstall is going to be my only option if none of these work. Here are some images you might find useful: https://ibb.co/wqS5xLN, https://ibb.co/pv7n1xqj, https://ibb.co/fY5t9sD9, https://ibb.co/dsMjky1j, and https://ibb.co/MDgq0qFB. I really hope these help you out of this situation. Any other tips would be a huge thank you to me too!
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Tomcastle88
03-22-2026, 08:28 AM #3

Hey, thanks so much for getting back to me. That was really helpful. I followed your advice and tried all the bootrepair options that came with Windows. I also looked at a few other steps but haven't been able to figure out how to remove just one drive while keeping the rest connected yet. The main problem is my C: drive, which isn't actually labeled "C:" anymore; it's showing up as F:. I've tried everything else I can think of and I'm really stuck on what to do next. I guess a full reinstall is going to be my only option if none of these work. Here are some images you might find useful: https://ibb.co/wqS5xLN, https://ibb.co/pv7n1xqj, https://ibb.co/fY5t9sD9, https://ibb.co/dsMjky1j, and https://ibb.co/MDgq0qFB. I really hope these help you out of this situation. Any other tips would be a huge thank you to me too!

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Xergxilla
Junior Member
5
03-22-2026, 02:43 PM
#4
Please make sure that your C: drive is a Windows installation drive and it is plugged into the SATA 1 port on your motherboard. Keep this drive connected and disconnect other drives before trying to start your PC. Try to turn on your computer and see if it talks to the BIOS, then check your boot order so your Windows drive (your Samsung EVO 860 SSD) boots first. Then try starting up again. If everything works fine you can shut down and plug in your other drives. I agree with Lutfij to clear the memory cache and see if things change. Please let me know how it goes and tell me if all problems are fixed or if we need more help. Thanks.
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Xergxilla
03-22-2026, 02:43 PM #4

Please make sure that your C: drive is a Windows installation drive and it is plugged into the SATA 1 port on your motherboard. Keep this drive connected and disconnect other drives before trying to start your PC. Try to turn on your computer and see if it talks to the BIOS, then check your boot order so your Windows drive (your Samsung EVO 860 SSD) boots first. Then try starting up again. If everything works fine you can shut down and plug in your other drives. I agree with Lutfij to clear the memory cache and see if things change. Please let me know how it goes and tell me if all problems are fixed or if we need more help. Thanks.

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LucasandClaus
Senior Member
438
03-23-2026, 01:56 PM
#5
It looks like your hard drive is set up as a boot file system with the main Windows files on it. You have Windows installed in a special setup where the built-in computer software doesn't work because the UEFI setting is turned off or disabled. Just remove any other hard drives and keep that one alone, then try again.
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LucasandClaus
03-23-2026, 01:56 PM #5

It looks like your hard drive is set up as a boot file system with the main Windows files on it. You have Windows installed in a special setup where the built-in computer software doesn't work because the UEFI setting is turned off or disabled. Just remove any other hard drives and keep that one alone, then try again.

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loliminer2012
Member
61
03-29-2026, 06:34 AM
#6
Hi everyone, thank you so much for all your help. Just following up on this topic. After trying everything and getting stuck in loops, the problem was clear: the M.2 boot drive wasn't working right. I didn't get the PC to start from it. So I bought a new M.2 drive plus an external USB 3.0 M.2 adapter so I can connect an M.2 drive to my PC through USB, and that's still not happening. It's weird though; I could see the drive in the BIOS screen but when I tried to check it inside Windows Setup, it didn't show up. Bottom line: I just couldn't spend more hours debugging, so I used the new M.2 drive to fix the PC and now everything is working smoothly. Thanks for all your time. One day I hope I'll have enough time to figure out what was wrong with that old M.2 drive but if not, it's just making a nice decoration on my desk. Thanks again!
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loliminer2012
03-29-2026, 06:34 AM #6

Hi everyone, thank you so much for all your help. Just following up on this topic. After trying everything and getting stuck in loops, the problem was clear: the M.2 boot drive wasn't working right. I didn't get the PC to start from it. So I bought a new M.2 drive plus an external USB 3.0 M.2 adapter so I can connect an M.2 drive to my PC through USB, and that's still not happening. It's weird though; I could see the drive in the BIOS screen but when I tried to check it inside Windows Setup, it didn't show up. Bottom line: I just couldn't spend more hours debugging, so I used the new M.2 drive to fix the PC and now everything is working smoothly. Thanks for all your time. One day I hope I'll have enough time to figure out what was wrong with that old M.2 drive but if not, it's just making a nice decoration on my desk. Thanks again!