Disk Manager can set the "active" flag for a Primary
partition on its local disk. That marks the partition which
contains the Boot Sector that invokes the boot manager.
In the OP's case, he hasn't designated which HD should
have its MBR get control at boot up. The way that that
is done depends on the particular BIOS in the machine.

*TimDaniels*

"Rick Rogers" wrote:
The old drive is still the active one. You have to change the
active volume in disk manager (diskmgmt.msc) and then run
a startup repair, preferably with the old drive temporarily
detached.


"CJM" wrote:
I've upgraded my machine at some point in the last year,
where I added a new 500GB drive and moved my C:
partition across to it. The previous 250GB drive was left in for additional
storage.

Just recently (while upgrading my BIOS) I realised that
my system was still booting from the 250GB drive even
though Windows was on the other disk.

There is a fair possibility in the not too distant future that
I'll replace the 250GB disk with a larger disk, in which
case I won't be able to boot. Is there a safe and reliable
way to change it so that the system boots from the 500GB
disk?

CJM