Monitor brightness–or not
In this post
http://msmvps.com/blogs/richardsiddaway/archive/2011/06/26/1795135.aspx?CommentPosted=true#commentmessage
I discussed using WMI to check the monitor’s brightness. Further investigation has shown that not all monitors support the interface to WMI so it is a bit of trial and error to check if it does work on your machine