title: Do .NET Environment Variables get deleted
body: <p>I need to store my AWS Access Keys somewhere private, and read via code, not stored in it. I'm thinking on storing them in <a href="http://msdn.microsoft.com/en-us/library/vstudio/System.Environment.SetEnvironmentVariable%28v=vs.90%29.aspx" rel="nofollow">EnviromentVariabels</a>, but from the description, it makes it unclear if they are only kept until the application is restarted, or stored in registry until over written.</p>
  
  <p><code>Creates, modifies, or deletes an environment variable stored in the current process</code></p>
  
  <p>and</p>
  
  <p><code>Creates, modifies, or deletes an environment variable stored in the current process or in the Windows operating system registry key reserved for the current user or local machine.</code></p>
  
  <p>Are they kept for good, or even is there a better way of saving them?</p>