After installing Windows on another drive I'm no longer able to boot into my main drive, what happened?

[apav]

Hi guys,

So I'm no longer able to boot into my main drive, but all my files and folders on that drive still look intact. I honestly don't know what went wrong or if there is any way to fix this other than reinstalling Windows. Tried startup repair on my Windows 10 installation USB, that failed. I'll explain every step I took.

I should first mention I just built this PC and I bought an M.2 SSD to use as my main drive, but I also installed my SATA SSD from my old PC. After installing Windows 10 on my M.2 drive I was able to select which drive I wanted to boot into every time I started my PC. I didn't format that SATA SSD until just before when I went to install another copy of Windows on it. Here's what happened.

I booted into my installation USB. My main drive (the M.2 SSD) was called drive 2 and my other drive (the SATA SSD) was called drive 0. I formatted then deleted the main partition of drive 0, then deleted all the smaller partitions of reserved space so the drive only had one volume of unallocated space. Then I selected that unallocated space and selected new, which recreated all the smaller partitions. I then selected the main partition of drive 0 and pressed next, which installed it on that drive. It installed successfully, but I first noticed something was odd when I didn't see the boot manager after I restarted my computer, it just automatically boots to the new copy of Windows. I noticed in my BIOS the boot order has the boot manager for my SATA SSD as the first and there's no boot manager for my M.2 SSD. Every time I try to boot into my M.2 SSD I just get a black screen with a flashing underscore symbol that moves back and forth between the top left and near center of the screen. I disconnected my SATA SSD so it could only boot to my main drive and the same thing happens. 

Anyone know what went wrong here? I never touched my main drive when I formatted, deleted and recreated partitions on my SATA SSD, and that one boots just fine. And are there any other steps to fix this before I just give up and reinstall Windows on that drive? Thank you.

[MorganO]

10 minutes ago, apav said:

Hi guys,

So I'm no longer able to boot into my main drive, but all my files and folders on that drive still look intact. I honestly don't know what went wrong or if there is any way to fix this other than reinstalling Windows. Tried startup repair on my Windows 10 installation USB, that failed. I'll explain every step I took.

I should first mention I just built this PC and I bought an M.2 SSD to use as my main drive, but I also installed my SATA SSD from my old PC. After installing Windows 10 on my M.2 drive I was able to select which drive I wanted to boot into every time I started my PC. I didn't format that SATA SSD until just before when I went to install another copy of Windows on it. Here's what happened.

I booted into my installation USB. My main drive (the M.2 SSD) was called drive 2 and my other drive (the SATA SSD) was called drive 0. I formatted then deleted the main partition of drive 0, then deleted all the smaller partitions of reserved space so the drive only had one volume of unallocated space. Then I selected that unallocated space and selected new, which recreated all the smaller partitions. I then selected the main partition of drive 0 and pressed next, which installed it on that drive. It installed successfully, but I first noticed something was odd when I didn't see the boot manager after I restarted my computer, it just automatically boots to the new copy of Windows. I noticed in my BIOS the boot order has the boot manager for my SATA SSD as the first and there's no boot manager for my M.2 SSD. Every time I try to boot into my M.2 SSD I just get a black screen with flashing dots. I disconnected my SATA SSD so it could only boot to my main drive and the same thing happens. 

Anyone know what went wrong here? I never touched my main drive when I formatted, deleted and recreated partitions on my SATA SSD, and that one boots just fine. And are there any other steps to fix this before I just give up and reinstall Windows on that drive? Thank you.

tldr?

did you install windows on both drives?

[apav]

42 minutes ago, KOMTechAndGaming said:

tldr?

did you install windows on both drives?

TLDR is I had two Windows 10 drives on one computer that both booted fine, but after reinstalling Windows 10 on one drive I'm no longer able to boot into the other drive. When I try to boot into that drive I get an infinite black screen with a flashing underscore symbol, but all the files and folders look intact on that drive. Startup repair didn't fix it.