Dunno....
But have you tried setting up a shedule to open file1 in 5 minutes from now
and file2 in, say 7 minutes?
There are, I think at least 3 ways that you can see how many instances you
are running:
1) I think its true in 2003 that when they are both open, if you look in
Windows/switch windows only the file running in that instance will show, in
which case you can ctrl-F6 between them. In other words, if two files are
open in 2 instances, you won't be able to ctrl-f6 between them.
2) Have a look in Task Manager- Applications tab which should tell you how
many instances are running.
3) If that isn't immediately clear, try closing Excel by clicking just once
on the red X close box - the "outer one" for Excel, not the "inner one" for
the actual file. If both files are closed by the one click, you had only one
instance running, but if one file remains open, you have closed one instance
and have one instance still open.
Hope I've hit the mark for you.
Cheers