Bios will recognize all drives, but won't allow me to boot from two (including the one with OS)

[devhesinter]

I built a computer a few days ago. It was working fine until this morning it shut off a couple times while gaming. Pretty sure it was a PSU issue (I reused an old one) since I was cutting it close in the first place, so I went to go buy another (750w). So I put it in, and attempted to boot my computer.

Now, I have 3 drives, a 500GB new SSD (samsung 850 evo, has OS + most of my programs on it), 128 GB old SSD (samsung 840, has absolutely nothing on it) and an old 640gb western digital hard drive (mostly old documents and videos)

By default, it tried to boot from my old 640 gb HDD. Said bootmgr not found, to be expected since there is no OS on that drive. I went to my BiOS (ASUS Z170-P) and though it listed all my drives, it only gave me the option to boot from my 640gb HDD. So I unplugged it. It then just wouldn't boot. I'd be greeted with a blank screen, my monitors flickering, then going back to the bios. I tried to boot override to my main SSD, and it would just bring me back to the bios.

Now, here's where the weirdest thing happened. I tried to boot from my 128 GB SSD (I actually accidentally clicked it, it has zero files on it, zilcho), and it started up. I replicated it a few more times after plugging all drives back in. Same thing happened, won't let me boot when I select my main SSD, but will let me boot when I select my blank secondary SSD.

I'm making my post from this computer right now. Windows and all programs seem to be working fine. Windows recognizes all three drives, plus my DVD drive and a flash drive I have plugged in (was about to reinstall windows)

What causes this? What should I do to fix this? Is it possible losing power a couple times damaged my motherboard and/or hard drives?

Thanks in advance.

 

[devhesinter]

bump, nearly dropped to page 2

 

[SuperSoph_WD]

Welcome to the TH community, devhesinter!

I'd recommend you check how the drives appear in Disk Management in Windows, since you were able to successfully boot into the system. Sharing a screenshot might actually help a lot as well.
You might be encountering some OS confusion issues. However, I'd suggest you check the boot order after you reset BIOS. You mentioned that it's a new build, so you should keep in mind that changing the motherboard requires you to use a brand new genuine Windows installation. The OS communicates with the mobo which is where the activation code is stored. If you haven't performed a clean install onto your new rig, I'd suggest you buy a genuine Windows copy and do it. This should fix your issue.

Hope this helps. Let me know if you have more questions!
SuperSoph_WD

 

[devhesinter]

Welcome to the TH community, devhesinter!

I'd recommend you check how the drives appear in Disk Management in Windows, since you were able to successfully boot into the system. Sharing a screenshot might actually help a lot as well.
You might be encountering some OS confusion issues. However, I'd suggest you check the boot order after you reset BIOS. You mentioned that it's a new build, so you should keep in mind that changing the motherboard requires you to use a brand new genuine Windows installation. The OS communicates with the mobo which is where the activation code is stored. If you haven't performed a clean install onto your new rig, I'd suggest you buy a genuine Windows copy and do it. This should fix your issue.

Hope this helps. Let me know if you have more questions!
SuperSoph_WD

Hey, thanks for the reply and the welcome.

Here's how they appear in disk management. C: Is my brand new 4 day old drive. E: is my old SSD that I wiped before putting it in here. F: is a 6+ year old HDD that was my secondary HDD in my last build and primary two builds ago.

The boot order has my primary SSD as priority, but the BiOS simply doesn't seem to be able to or want to boot from it. I can only get into the system by booting from my 100% empty secondary ssd. I will upload screenshots shortly.

I did do a clean install of Windows 10 on my primary SSD (its brand new), and I wiped my secondary, and my third has no operating system on it.

 

[mjslakeridge]

When you installed your clean copy of Windows 10 to your new primary SSD, did you have either of the other 2 drives connected at that time? You should not have them connected. It is possible that certain boot files got written to the secondary SSD, and that is why it only boots up when the secondary SSD is selected in BIOS to be the boot drive.

I would disconnect the other 2 drives and re-install Windows to the primary SSD, then power off the computer and re-connect the other 2 drives, and re-format the secondary SSD.

 

[devhesinter]

When you installed your clean copy of Windows 10 to your new primary SSD, did you have either of the other 2 drives connected at that time? You should not have them connected. It is possible that certain boot files got written to the secondary SSD, and that is why it only boots up when the secondary SSD is selected in BIOS to be the boot drive.

I would disconnect the other 2 drives and re-install Windows to the primary SSD, then power off the computer and re-connect the other 2 drives, and re-format the secondary SSD.

I accidentally set this as best answer instead of replying. Oops.
But yeah I had it all plugged in. I'll try reinstalling with nothing else plugged in shortly. But that still doesn't explain why it worked fine for the first two days.

 

[mjslakeridge]

I am pretty sure reinstalling with the other 2 drives disconnected will solve your problem. As you can see from your screenshot, there is something on your "empty" E drive, .11 GB. It is probably the MBR (master boot record files). As to why it worked the first couple of days - who knows.

This issue comes up about once per week here on Tom's. I can certainly see why, you have purchased all your parts, assembled everything and are excited to get the OS installed to see if everything works.

Edit: If reinstalling doesn't fix your problem, I can unselect the best answer so the thread wonn't appear as solved.

 

[ArtPog]

Just to make your PC life simpler and avoid these "curiosities' you've indicated, why not just do this...

1. Connect your boot drive - that's the 500 GB Samsung SSD - make no mistake about that - to your motherboard's first SATA connector which ASUS has designated in their wisdom the SATA6G-3 connector (port).

Without any other drive connected (as mjslakeridge has suggested) boot to the SSD and ensure it's functionally stable. You might want to access the boot menu (via the appropriate F key) during the boot and select the listed SSD.

2. Shut down the machine; connect whatever other drives you desire as secondary drives to the other SATA ports. Boot the machine to determine all is well.

3. You might want to take a look at that now-connected 120 GB SSD and format it.

 

[devhesinter]

Just to make your PC life simpler and avoid these "curiosities' you've indicated, why not just do this...

1. Connect your boot drive - that's the 500 GB Samsung SSD - make no mistake about that - to your motherboard's first SATA connector which ASUS has designated in their wisdom the SATA6G-3 connector (port).

Without any other drive connected (as mjslakeridge has suggested) boot to the SSD and ensure it's functionally stable. You might want to access the boot menu (via the appropriate F key) during the boot and select the listed SSD.

2. Shut down the machine; connect whatever other drives you desire as secondary drives to the other SATA ports. Boot the machine to determine all is well.

3. You might want to take a look at that now-connected 120 GB SSD and format it.

I've tried this. It just doesn't boot from my main 500gb ssd, even when its the only one plugged in.

 

[mjslakeridge]

ArtPog: You may have missed this earlier in the thread. The OP had the secondary drives connected when installing Windows, so the MBR "probably" got written to the secondary SSD. That is why it won't boot when only the primary SSD is installed. Your suggestions are fine if done AFTER the OP re-installs Windows to the primary drive with the others disconnected.

 

[slingsrat]

Your boot files are not on your 500GB SSD, that is obvious. And windows by default will not put the boot files on the same disk as the operating system when you install windows. I would just plug everything in and boot to windows then use easyBCD to move your boot sector to the drive you want.

 

[mjslakeridge]

Slingsrat: Didn't know about easyBCD. I see it is available as a download from a variety of sites. Will downloading it also result in a bunch of other "bloatware" getting installed? Is there a preferred download site?

 

[slingsrat]

Slingsrat: Didn't know about easyBCD. I see it is available as a download from a variety of sites. Will downloading it also result in a bunch of other "bloatware" getting installed? Is there a preferred download site?

No bloatware it is very good for MBR but not so for UEFI. I just get it from the Neosmart website.

 

[devhesinter]

Your boot files are not on your 500GB SSD, that is obvious. And windows by default will not put the boot files on the same disk as the operating system when you install windows. I would just plug everything in and boot to windows then use easyBCD to move your boot sector to the drive you want.

Doing exactly this worked. While the other solutions probably would have worked this was likely by far the easiest/quickest.

Thank you, good sir. Is there any way to select this as the best solution?

Still a bit curious as to why this didn't happen until a couple days after I build the computer when I replaced the power supply, though!

 

[mjslakeridge]

Now you should be able to Pick as the solution as I unselected my answer.

 

[devhesinter]

Now you should be able to Pick as the solution as I unselected my answer.

Much appreciated, and thanks again everyone.

 

[ArtPog]

Yes, I'm afraid I did misunderstand your situation

It seems clear that the necessary boot files for your 500 GB Samsung SSD (your intended boot drive) reside on the System Reserved partition of the 640 GB HDD. Apparently when you installed the OS onto the SSD your HDD was connected at the time and it's an anomaly with the Windows OS that the SR partition is (sometimes) created on a connected secondary drive instead of created on the intended boot drive.

It's the reason users are cautioned that wherever possible they should connect only the intended boot disk in the system and uninstall any other disks during installation of an OS.

Glad to hear slingsrat's solution resolved your problem.

 

[slingsrat]

Happy to help. But it is not an anomaly that windows puts the boot sector and OS on different drives if it can. There is a reason which eludes me for the moment.

 

[ArtPog]

Happy to help. But it is not an anomaly that windows puts the boot sector and OS on different drives if it can. There is a reason which eludes me for the moment.

Well, if it's not an "anomaly", it has certainly caused a great deal of grief for I-don't-know-how-many-thousands-of-PC-users over the years.
To my knowledge I have never seen any clarification from Microsoft reps. Should you come across one I trust you will bring it to our attention.