USB SSD unable to make bootable

[winabbey]

I purchased a portable Samsung SSD T7 (1 TB) to use as the Windows and program storage on my HP ProDesk 400 G1 SFF desktop.

Using the Samsung Data Migration tool the contents of the existing internal HDD has been cloned to the new T7 SSD. After altering the BIOS to boot from the T7 I get a bluescreen error with Stop Code: Inaccessible Boot Device. 

What do I need to do to have the SSD boot as the primary drive?

There's suggestions online of having to rebuild the BCD on the cloned disk. I'm not sure of the steps to do this.

The instructions for the Samsung Data Migration tool don't mention anything beyond actual creation of the cloned drive.

[BeemerBiker]

Did you disable "secure boot" in the bios? 

Make sure it is disabled.

I assume you have UEFI bios.  The bios may list several boot optoins

windows boot manager

Seagate

Windows 10

drive0

-etc-  

Usually the best bet is the windows boot manager but try others if that does not work.

If none of the above work you may need to boot the win10 recovery USB (DVD?) and try a boot repair

[winabbey]

Many thanks for the suggestions but haven't solved the issue as yet.

Yes, it is UEFI BIOS and Secure Boot was already disabled.

The boot sequence doesn't appear to be the problem as it tries to boot from the SSD but always gives the same blue screen error message. Unplug the SSD and the system boots normally via the hard disk.

I'll investigate Boot Repair. Other suggested fixes most welscome.