I don't know what the network inventory Software is and from where to get it for free, let me know the features of network inventory Software from where should I download it for free?
What Are The Features Of The Network Inventory Software Free?
Following are the features of the network inventory Software
• Automate your scan
• Track your Software
• Report if there are some issues
• Manage your mobile devices
• Stay updated
• Network Tools
• Track your user
You can download it from the following link
http://www.spiceworks.com/free-pc-network-inventory-Software/#features
This is a free and good site.