boot problem

[Bob]

I have replaced an old computer (BIOS not UEFI) with a new one, Lenovo 5
Desktop 90NA001DUS.  Moved the hard disk from the old computer to the new
computer.  Booting a USB live CD it shows the disk drive is SDA which it was in
the old computer.  I moved the disk drive to boot before the SSD which contains
win10.  I have disabled security boot in the new computer.  The system still
boots win10.

Any ideas on how to get this disk drive to boot?

-- 
Robert Blair


Did you ever notice: When you put the 2 words ' The'   and ' IRS ' together it spells   'Theirs...'