Now Im customizing title bar of my application. My aim is to add one extra button on title bar. Im my previous question people have adviced me the way I can customize non c
I don't think it's possible to draw beyond your NC area, and I kind of doubt they are drawing the whole UI to exactly match DWM Aero effects.
Given how this looks, I wonder if they did some tricks with either the help or restore button of a CustomBorderForm, which would then get the DWM blur highlight effect "for free".
Here's the most relevant article I could find to this: http://geekswithblogs.net/kobush/articles/CustomBorderForms3.aspx
Followup - I think this custom chrome thread has more pointers to the same techniques (although different goal): Custom titlebars/chrome in a WinForms app
Skype cheats it, and has a little sliver along the top of their window; where they can draw it.
You can see it with Process Explorer to SpyXX:
MSDN: Custom Window Frame Using DWM
AFAIK, this is not possible, because the area outside your window's border simply does not belong to you.
The Skype screenshot is from a custom-drawn frame that most likely extends a bit beyond the visible borders, not from an Aero Glass frame. You can tell the difference if you look carefully.