title: How to get installation path of an application?
body: <p>In Windows using C#, how can I get the installation path of a software (for example consider NUnit or any other software like MS word, etc.) <strong>from my project</strong>? Also how to set the path variables that we set in Environment variables so that we can run the application just by giving in command prompt. </p>
  
  <p>Like if I install NUnit in "C:\Program Files" I can run it by giving 'NUnit' in cmd prompt but if I install in a different location I can't do the same. 
  <strong>I need to get the location or path of NUnit or any other software installed in my system (having Windows XP) from my project.</strong></p>
  
  <p>EDIT:
  Like I can get the path of installed program from registry. 
  HKEY_CURRENT_USER->SOFTWARE</p>