SENS events

I decided to write very small program that would calculate how much time someone spends at computer. Not too sophisticated, just based on login-logout time and screen saver. Researching the subject I found that this days it should use System Event Notification Services (SENS) to be able to work on Windows Vista. And then I had very hard time figuring out how to make it work based on MSDN information.

What helped me is this article, particularly example.

http://dotnet.sys-con.com/read/105651_1.htm

The program is not written, but link is still good. And I tried example, it works.