A technician needs to install an NVMe drive in an old computer using a PCIe 4X card. The technician installs Windows on the drive and reboots the computer. An error message appears stating there is…

While a boot partition not being active can cause boot issues, the problem description states the technician 'cannot select the new drive as a boot device' in the BIOS, indicating a deeper recognition issue, not just a partition flag.

Older computer BIOS/UEFI firmware often lacks native support or specific drivers required to recognize and boot directly from NVMe drives, especially when NVMe was not a common boot device option at the time the motherboard was manufactured. Even if the NVMe drive is recognized for data storage, the BIOS may not be able to hand off the boot process to it without the appropriate NVMe boot support.

An NVMe drive with an MBR partition is less likely the primary issue than a lack of BIOS support for NVMe booting itself, as modern Windows installations would typically use GPT for NVMe.

An NVMe drive being out of space would not prevent it from being selectable as a boot device in the BIOS, nor would it cause a 'no bootable device found' error immediately after a fresh Windows installation; it might cause issues later during OS operation.