Question NVMe M.2 SSD and its Windows installation disappeared after installing a hard drive?

[normalguy33]

I installed a hard drive from an old PC and now Windows won’t boot from my M.2 SSD anymore

My PC was working fine until i put in an HDD from an old PC. I thought it would continue booting from my M.2 and recognize the new hard drive as additional storage, but Windows started from the HDD instead. I went back to the UEFI to check the boot settings and I get the “Reboot and select proper boot device” error when I boot from the M.2.

Booting from the HDD works, but my M.2 does not show up as a storage drive. It also shows as “Not Installed” in the “APU SATA Port 0” section of the UEFI. It does, however, show up in the NVMe Configuration section with the correct info about the SSD.

I’ve tried booting with the HDD in different SATA ports, booting with the HDD disconnected, resetting the CMOS. Windows Installation Media shows the M.2 drive with Windows installed, but it can’t restore it.

Are my original Windows installation and all my files gone? How can I make the PC boot from the M.2 again? All the files are still there, adding a new hard drive shouldn’t have wiped everything.

 

[normalguy33]

I can get as far as being able to clean/format the M.2 and reinstall Windows using the installation media. I’d prefer not to do this, and I’m not sure if this would even work, but it seems like that’s my only option.

 

[USAFRet]

Need details on all the hardware involved.

If you remove the old drive you connected, does the system work properly?

 

[normalguy33]

Need details on all the hardware involved.

If you remove the old drive you connected, does the system work properly?

Motherboard: Gigabyte B450M DS3H

Storage: ADATA XPG SX8200 512GB

Windows can not boot from the M.2 even with every other drive disconnected