Re: Software Audit
Look into Spiceworks. You can install it on a host PC or server, and then set it up (easily) to perform software inventory of all the connected PCs. The outputs are easy to use, and you can really get a good idea of what is going on with your network. It works best on an Active Directory Domain environment, but I use it at home with a mixed network (both active directory and standard workgroups)
As long as the software knows which accounts it can use to log into systems in a non-domain environment, it can poll each PC. It's also useful because it includes things like a helpdesk ticketing system, community support (separate from these forums) and the ability to run plugins and other programs to tie into the environment.
Yes, totally free.