title: Where do programs save their secret license?
body: <p>Where do programs save their secret license or install related information? I notice that often times when you uninstall a program, clear out appdata references, check registries to make sure there is no residue of any relevant information.</p>
  
  <p>If you reinstall the trial program again, it seems to know it was installed before. I'm not looking to find a way to crack trial programs but actually need to implement something similar and can't find any good information on how to do this.</p>