Both ARCServe and ADSM provide their own SCSI driver for their tape
devices.  Each product (last time I looked) claims exclusive ownership
of the device.  You may very well find that you cannot have these (or
any other?) products active simultaneously in one system.  To change
from one to the other will require a reboot of NT.

Whether the products can co-exist from the point of view of the data
on the clients does depend on which components you activate.  If you
are archiving, for example, then trying to retrieve data, obviously
they cannot as neither would be able to determine which owned the
archive copy.

Murray Nicholas
IT Systems Consultant
Galeforce Information Services Pty Ltd
email:  murray AT galeforce.bu.aust DOT com
www:    www.bu.aust.com/galeforce