"Aero Glass" is a new feature which allows Vista to show aero effect like the snapshot.
How to turn on or turn off it?
[My Computer]--> [Advance Setting] --> [Performance Setting] --> [Video Effect] --> [Enable Desktop Composition].
How to use "Aero Glass" to blur a Window?
DwmEnableBlurBehindWindow and DwmExtendFrameIntoClientArea.
For more detail information to refer