With an old laptop, I cloned the OS HD to an SSD with Macrium Reflect, both harddrives are mounted inside the laptop. When I enter the BIOS, I wanted to select the SSD as the first boot choice ...

Let's take a quick look at a step-by-step guide detailing how to turn an SSD into a boot drive for your new or existing computer.

Read: Hard Drive not showing up on Boot Menu in Windows Those were a few ways to fix hard disks or partitions not detected when installing Windows 11.

If your computer doesn't detect NVMe SSD, verify the connection, change drive letter & format SSD, etc to fix NVMe SSD not detected issue.