The title bars and window frames aren’t transparent.
When I open the color mixer in Personalization I also don’t see no “use transparency” setting or whatsoever.
But all the required things (that I know of) are enabled, Desktop Experience is installed, the themes service is running and everything seems to be fine, even the taskbar is transparent but not the window frames (title bars)….
I use Windows Server 2012 Standard Edition (the officially released version).
It worked fine with Windows Server 2012 Release Candidate…