title: How to predict the next GUID from a given GUID?
body: <p>I have sent 10000 mails to our customers and each mail had a link of the format </p>
  
  <pre><code>http://example.com/LogIn?key={guid}
  </code></pre>
  
  <p>Unfortunately the <code>guid</code> I sent were random guids (test data generated by <code>Guid.NewGuid()</code>) so the customers have all received invalid links...</p>
  
  <p>Based on the 404s i receive from the webserver I have a few guids that I sent out. I have read that the guid generator in windows is weak so you can predict the next guid from one you already have. Does anyone know how? If i could do that I could make the guids I sent out valid so the links would work again.</p>