Per their site:
The Secunia Software Inspector will inspect your operating system and software for insecure versions and missing security updates. A default inspection normally lasts 5-40 seconds, while a thorough inspection may take several minutes. Note: If you have anti-virus software or similar enabled, an inspection may increase significantly in duration.
This is a great tool for:
1. a quick verification of an imaged (or re-imaged) workstation or server.
2. establishing a quick baseline (or does your baseline need to be updated?)
3. a simple first step to hardening a development, security, or customer workstation / laptop.
Access the tool here. Tested on Windows only.
Remember to check the "Enable thorough ..." check box, as shown below.