Hi.
Im just not finding any info. Does actual windows gui (controls, windows frames, dlgboxes) uses direct2d (what about the text on those)?
I remember reading about this somewhere..

Also, does the visual styles change anything about this? Like windows aero uses hardware acceleration, but if you deactivate it, it uses the cpu(old GUI stuff). That would mean is better activating it in your app isnt it? Since you need do this manually...With brings me another question: not activating it on your app is the same as having it deactivated on the SO visual configs or its really just a visual thing (like what matters is the SO configs, activating or not in the app is just a visual thing)

It dependes.
Previous to Windows 8, windows forms and other default windows controls used GDI.
With WPF and metro apps, Microsoft seems to be favoring DirectX instead.

That would mean is better activating it in your app isnt it?

Yeah, hardware acceleration usually has better performance than the software counterpart.
You actually don't have to do anything in relationship to the Aero Visual Style, sinse the OS takes care of it. You can try it on the control panel and adjust the settings.
Hope this helps ;)