title: Uniquely identify PC based on software/hardware
body: <p>For a requirement to generate per-PC license keys, I need some code which will return a stable and (near) unique key on any PC. It doesn't <em>have</em> to be guaranteed unique, but close. It <em>does</em> need to be reasonably stable though, so that a given PC always generates the same result unless the hardware is substantially changed.</p>
  
  <p>This is for a Windows application, using wxWidgets but a Win32 or other option is fine.</p>
  
  <p>I was thinking about MAC address but what about laptops which can routinely disable the network card in power-saving mode? I came across <a href="http://msdn.microsoft.com/en-us/library/ms724311(VS.85).aspx" rel="noreferrer">GetCurrentHwProfile</a> but it doesn't quite look like what I want?</p>