Performing a network audit.

OK boys and girls, here is my question…

I am trying to find a program that will audit a network, as in Servers and desktops, what hardware is in them and what software is installed on the HDD, WITHOUT client software being previously installed on the systems. I know we can use Altiris, or SMS or Zen or any of a few others, but they require client software to be previously installed to reply to query, does anyone now of a utility or anything that can perform this task, without client software on the machines? Thx to all!

directionseeker.