Lansweeper is a free to use tool that allows you to scan your Windows network and create its hardware and software inventory.
    Unlike other common application this tool does not need any client installed on your workstations. With the help of this powerful software that performs all scanning through the WMI, file shares and remote registry access you can easily make a complete software and hardware asset inventory for your Windows network. You can use this application on multiple servers and with unlimited clients. This application has the capability to provide you with reports that include; of over 80 hardware, software, network and server reports. Other than that you can use this tool for: Software and operating system licensing reports, cost calculation, scheduled scanning, alert reporting and so on.
    This efficient utility is also provided with additional feature to find malicious processes, spyware, browser hijacks, and so on running in your company.