Brian

If they start a second instance of Excel and open the second file in
the second instance of Excel they may have what they want.  Since you
can view both in the same instance of Excel (by using Windows-Arrange)
I don't often like to have two Excel instnace running; the one
exception is that when using two monitors and wanting to take
advantage of both, I have found that I can only do so with two
separate Excel instances.

Another point about arranging windows, if you elect horozontal, they
get stacked on top of each other and if you elect vertical they go
side to side.  that seems backwards to me, but, i am finally getting
used to it.

Good luck.

Ken