2.5" Crucial SSD not appearing in boot order in BIOS

[EquanimousBosch]

Hello!

I'm trying to boot from my new Crucial SSD. I cloned my old drive from the M.2 SSD that came with my laptop using Acronis. The new drive is initialized. It appears in Disk Management and File Explorer, Windows still boots from the old M.2 drive. 

I update Windows, I updated BIOS, I tried the SSD connected to the internal SATA cable as well as an external SATA-USB cable on my computer and my wife's computer. I tried re-cloning the drive and doing it all again fresh.

I tried disabling secure boot and enabling legacy support. this is the only time the SSD appears in BIOS (under Legacy Boot Order>Internal Hard Drive) but even if I bring it up to the front of the line, the computer still just boot from the old M.2.

I tried removing the old drive, and the computer won't boot up at all. It goes right to the diagnostic screen and won't even get to Windows. 

Can anyone help??

Thanks in advance!

[WAWood]

@EquanimousBosch 

You probably have several different issues causing this problem.

First, the PC most likely came preconfigured to use UEFI, not Legacy, because of the M.2 SSD as the boot drive.  So, changing it to legacy, if that was the case, will guarantee that the new drive will not boot.

Second, you said you cloned the old drive, but I quite using Acronis hears back when I found such functions to be unreliable.  Are you positive that you cloned the ESP partition, not just the OS partition?

Third, Macrium Reflect makes a free utility you can use to migrate the boot files from one drive to another, and in the process, this resets the BIOS to boot from the new selected drive.

You need to follow the instructions below to create boot media from Macrium Reflect (MR) that can be used to rewrite/repair the boot media on your PC:
1) Download and install Macrium Reflect (MR) from this link on a working PC: http://www.macrium.com/reflectfree.aspx
2) Use the option to create a boot USB stick or CD

That will create MR bootable media. Then, you can boot your PC into WinPE using that media.

Have patience, as that can take a while to start and bring up the screen.

Once the screen is there, select the option to Fix Windows boot problems. It will then search for the OSs installed and list them, Select the one you want to repair and click Next.

It will now do the repairs, listing the things it has done.

When finished, select the option to Restart the PC.

If this worked, the boot repair succeeded and you should then be booting from the new drive.

[EquanimousBosch]

First of all, thanks so much for your help. 

Should I create the bootable media on the Crucial SSD or on a separate drive like a USB?

Then, when I repair, am I repairing the Crucial SSD with the cloned data on it, or my old drive?