Switched out my second hard drive… now I can't boot up. Help?

Software Issues Forum
1

I have my operating system on an M.2 SSD. I swapped my old secondary HDD for a new one, and now my laptop won’t boot from the M.2 drive anymore. The M.2 drive isn’t even showing up in the boot menu.

I installed Windows on the new HDD to test things, and when I boot into that, I can still see and access the M.2 drive files just fine.

Here’s a screenshot of my setup.

How do I fix this so I can boot from the M.2 again?

SOLUTION:

Here’s a guide I followed to fix it.

2

This sounds similar to an issue I had. Just because the OS is on the M.2 drive doesn’t necessarily mean the boot partition is there too. Sometimes the boot partition ends up on another drive, especially if multiple drives are installed during the OS setup.

Look at your drives. Does the M.2 have a system partition? If not, that could explain why it’s not booting.

You might need to reinstall Windows on the M.2 drive with only that drive connected. That way, the boot partition will be created there, which is a cleaner setup.

3

@Cade
The HDD I swapped out never had an OS on it. Why would the boot partition not be on the M.2? That doesn’t make sense to me.

So, do I need to figure out how to make a boot partition on the M.2?

4

Charlotte said:
@Cade
The HDD I swapped out never had an OS on it. Why would the boot partition not be on the M.2? That doesn’t make sense to me.

So, do I need to figure out how to make a boot partition on the M.2?

That’s odd if the old HDD didn’t have an OS. But either way, it looks like the boot partition isn’t on the M.2.

To fix this, you’ll probably need to reinstall Windows on the M.2. It’s the easiest and safest way to make sure the boot partition ends up there.

5

@Cade
You might not have to reinstall if you’re comfortable with some more advanced steps. It’s possible to create a boot partition on the M.2 manually.

Here’s the basic idea:

  1. Shrink the existing partition to make space for a new one.
  2. Create a new FAT32 primary partition.
  3. Use the command bcdboot c:\windows /s G: /f uefi (adjust for your actual drive letters).

You can do this with a Windows repair tool or bootable USB. Be careful though—if you make a mistake, it’s easy to mess things up.

6

@Adair
Does the boot partition need to be physically located before the OS partition on the drive? I thought shrinking partitions only worked at the end, not the start.

I’d personally just reinstall Windows on the M.2. Less chance of breaking things, and you’ll end up with a proper setup.

7

@Adair
Thanks for the suggestion. I actually followed the steps in this guide, and it worked!

8

Could the EFI system partition have been on the old secondary drive? Check Disk Management to see if it’s missing from your current setup.