[SOLVED] Weird interaction with SDD and HDD

[Mockingjason]

Hello. After accidentally deleting all of my Hard Drive's Partitions through the Windows OS Installer, I haven't been able to even see my HDD recocnized at all. Since it was an almost empty drive, I didn't really care about it, until now. So here's where things get weird. Whenever I unplug my HDD's SATA Cable from the Motherboard, my System will not be able to boot from my SSD, even though it recognizes it. I get a message reading: "Reboot and Select proper Boot device". If I plug the SATA Cable back in, it boots up like normal, but I still can not see my HDD.
Notes: Ny SSD is an NVMe M.2 Drive.
If I unplug the SATA cable while my computer is still running, everything works normally until I restart my system, which then greets me with the "select proper boot device" message.
Any clue on what is going on?

 

[jay32267]

I've seen this happen....or very similar things happen......when Windows was installed with more than one drive connected.

 

[rgd1101]

can't see it in windows explorer? or device manager?

 

[Mockingjason]

can't see it in windows explorer? or device manager?

Windows explorer, on device manager it shows up normally. But as I said, if I unplug it, the SSD becomes useless.

 

[rgd1101]

check disk management? might need to assign a letter.
like @jay32267 said, sound like it have a boot partition on the hdd.

 

[Mockingjason]

check disk management? might need to assign a letter.
like @jay32267 said, sound like it have a boot partition on the hdd.

This is my Disk Management page. Disk 0 is my HDD, Disk 1 is my SSD. The HDD is unallocated.

 

[Mockingjason]

check disk management? might need to assign a letter.
like @jay32267 said, sound like it have a boot partition on the hdd.

Also, I don't really care about the HDD working. All I want to know, is why my SSD can only be booted up from when my HDD's SATA Cable is plugged in.

 

[rgd1101]

see the 100MB healthy EFI system partition

 

[Mockingjason]

see the 100MB healthy EFI system partition

What about it?

 

[Mockingjason]

see the 100MB healthy EFI system partition

Hello again. So, I fixed the issue with me not being able to see/use my HDD. But the other problem I stated is still happening. Whenever I unplug my HDD, I get the "Select proper boot device" error. Any help?

 

[Mockingjason]

see the 100MB healthy EFI system partition

Hello?

 

[SkyNetRising]

What about it?

That small 100MB EFI system partition on HDD is bootloader.
Without it your system is unbootable.

If you disconnect HDD, bootloader is not available anymore and you can't boot into windows.

Note - do not connect/disconnect internal storage devices, while system is on. That can only be done with removable devices and you have to remove them safely first.