I have created an image by Macrium for my entire hard disk which has five partitions:
C(O.S), D:(DATA) are logical
System partition, Recovery partition and HP tools partition are primary
I restored all the partitions to another external hard disk
So, I think now I can boot from either of the internal hard disk or the external hard disk as long as both contains the same OS.
However, when I tried chpriority prerioty of booting devices in BIOS so that first boot device is the external hard disk and the internal hard disk is the second. So the Oexternal exteranl hard disk should be booted.
But the reverse has been happened. The OS on internal hard disk always booted, However first boot device is external hard disk.