Windows 10: PC won't boot unless an empty HDD is connected

So my HDD of almost two years seem to be acting...weird lately. I checked it out with CrystalDiskInfo, and it didn't look good.



I searched the internet on what that means, and it looks like it needs to be replaced. Unfortunately, I can't get a new one at the moment. But I do remember that I have an old HDD (320 GB) that I used to use. The one that I replaced for this new one (500 GB).

I plugged it in, and it works! So now I have two HDDs, but I decided to reinstall Windows 10 on the old one (320 GB) because it wasn't broken. So I wiped the new one (500 GB) and put everything in the old one (320 GB).

Now, I recently encountered a BSOD memory management error. I didn't know what it meant, but I thought the new HDD (500 GB) had something to do with it. So I disconnected it (but left it in the CPU), leaving only the old HDD (320 GB).

I thought, well the new HDD (500 GB) was basically empty, so if I disconnected it, nothing will happen, right? But when I booted it up, I got a Reboot and select proper boot device screen. I tried everything (reattaching stuff, selecting the HDD on startup), but the only thing that worked was reconnecting the new HDD (500 GB).

Can anyone help me out on this? Why does it still need the empty HDD when everything including Windows 10 is on another HDD?

Please post a screenshot of your Disk Management with both drives connected. I suspect that Windows put the boot files on the "empty" drive.

So apparently it does show the EFI System Partition on the "empty" HDD. Is that the culprit?

Yes. You can try the steps at Moving / recreating EFI partition - Windows 10 Forums to put the EFI partition on your Windows drive. Or you can just disconnect the 500GB drive and do another clean install.

Did you happen to have the 500GB drive plugged in a lower SATA port number than the 320GB (e.g. the 500GB was in SATA-0 and the 320GB was in SATA-1) when you installed Windows?

PolarNettles said:

Yes. You can try the steps at Moving / recreating EFI partition - Windows 10 Forums to put the EFI partition on your Windows drive. Or you can just disconnect the 500GB drive and do another clean install.

Alright, thanks! I'll follow up when I've done this.

PolarNettles said:

Did you happen to have the 500GB drive plugged in a lower SATA port number than the 320GB (e.g. the 500GB was in SATA-0 and the 320GB was in SATA-1) when you installed Windows?

I guess. I haven't been paying attention to which SATA port they are plugged into, but I think I have the 500 GB plugged in on SATA-3 and the 320 GB on the SATA-4.

Does Windows install the EFI Partition on the first HDD it sees by SATA port number order?

Walpurgis said:

Does Windows install the EFI Partition on the first HDD it sees by SATA port number order?

I haven't found it documented anywhere but from experimentation it does seem like Windows Setup always puts the boot files on the first drive it sees regardless of where you're actually installing Windows.

Do you have active partitions on both disks? Set the partition of the disk you don't want to boot from to inactive if so and see if the system now works with the disk removed. Please backup first.