The new windows installer service that goes in with the new client is
responsible for at least one of the reboots.  Someone one the list said
awhile back that if IE5.5 exists on the  client already then a reeboot will
not be necessary.  I tried this one one client and it worked without a
reeboot.  We also tried putting the new MDAC(MS Data Access Components) this
added the windows installer service but in some cases it still required a
reeboot.  All in all its not very consistent behavior.  All NT boxen are at
sp5 at least (very few at 6a) and all were upgrades from ADSM client 3.1.7.
I blame the new MS code that is introduced in the new clients probably put
there for w2k support.

As far as scripting an install there is a lengthy one line command that
interfaces with the new MS installer service that can be used to install the
client in the background with no intervention (silent install)  On every
machine I've used the command on it caused a Dr Watson.  The install
finishes anyway and the client seems to operate just fine but I am not about
to release that out to the NT admins.  I am sure they will have a cow over
that.  So I just wrote up some docs to walk them thru the install.  So far
there have been no problems.  You may be able to get around the pop up by
directly running the setup.exe instead of the   .msi  file.

Jack