isolating new clone drive for 1st bootup

As Rod Speed has pointed out, the clone drive
resulting from a cloning of a WinXP system HD
should be the only drive with an a WinXP OS
on an active partition when booting it up for the
1st time. (Thereafter it can "see" and be "seen"
by another OS in the PC.) The hassle is that you
have to open the case, disconnect the cables to the
other drives, including the one that has just been
cloned, boot up the new clone, and then, usually,
open the case again and reconnect the other drives.

It would be a lot easier if one could just shut down
and then disconnect the other drives by use of a
physical switch to break the connection with their
power cables. That would avoid all the hassle of
opening the case and unplugging the other drives.

So, does anyone have any information that would
indicate if switching the power cables would work?

*TimDaniels*