Checking if the current user is active?

Question

Windows Live Messenger, Skype, the indexing service in Windows and the screensaver functionality in Windows all have a way of detecting when the user moves his/her mouse, or uses his/her keyboard to detect when they are active, and when they are not.

Is there a Windows API used for detecting if the user is present at his PC? What about proximity sensor APIs in Windows 8? Or is it required for me to actually detect if the user moves his mouse or uses the keyboard through existing Windows APIs?

Answer 1

I found a solution using this API.

http://www.pinvoke.net/default.aspx/user32.GetLastInputInfo

It delivered exactly what I needed.