I want to use the bulk installer to push out agents, however some systems are still NT 4 - is there a way to make sure the boxes don't reboot (NT 4 requires a reboot for the agent install?) when i run the installer?
I don't think so. If it is possible though it would have to be done via a response file.
Have you tried generating a response file on a machine and choosing no for the reboot now option (to see what gets put in the response file)?
Anyway, even if you can do it, the agent won't be functional until you actually
reboot the machine.