Why My Cloned SSD Not Detected on Windows 10 and How Can I Fix the Boot Issue

I restarted the laptop after the cloning was finished, and as a result, the old hard disk is no longer recognized. I inserted the cloned one, and the problem persists. Any theories as to what might have taken place? I'm running Windows 10. I'll appreciate it if anyone can give me some suggestions. Thank you.

You clone a failed hard drive onto an SSD. This probably means that there is some level of corruption in the clone. Better to rebuild and extract the data.

Is it possible that the drive was created/mounted in legacy mode, but the system is now set to UEFI or vice versa? If the original disk is Legacy, this will result in an error "No boot device found" or a similar error at startup. If so, switch the setting back to Legacy, and the drive should boot normally, albeit with file system errors.

UEFI uses GPT and only recognizes UEFI/GPT or FAT32 partitions as boot media. Some newer firmware will only boot to GPT-formatted internal drives. Most will boot GPT or FAT32 from an external device. Make sure the boot mode is set to the correct setting for the original hard drive.

You can quickly identify a GPT disk because it will have several partitions by default - one is an EFI partition - if this partition exists, then the disk is GPT. 

If it is an MBR disk, you can use EaseUS Partition Master to convert it into a GPT one. This tool allows you to convert MBR to GPT with three simple steps. I personally have used this tool several times. It helped me a lot. Try it!

After this process, you can use a third-party tool to recover your data from the cloned hard drive/SSD.