Lansweeper is a powerful freeware solution to make a complete software, hardware, asset inventory of your Windows network.
Network inventory advantages:
Automatic inventory of all your Windows clients.
No need to install an agent on your workstations. Scanning is triggered when a user logs on.
Active Directory user and computer details.
Reports on custom Registry Keys and custom File Information.
Find unauthorised software, unknown processes, browser hijacks.
Scan used software, track licenses.
Build you own custom reports.
All information is stored in SQL server (or in the free SQL Express version).