I am on Win8 Enterprise N x86 RTM. There are no options to turn use/not use transparent glass in either "personalize, color" or "adjust performance & appearance" menus. And there are no 'Aero themes' available to me to use as per the instructions. I downloaded the reg files for turning transparency on and off - but these had no effect.
However it isn't the window borders I am wanting to turn transparent/non-transparent, but the shadow around them (I believe this is called the ''drop shadow'', which I have seen referenced as being removed in Win8 because MS were getting rid of Aero artifacts). I'll provide some screenshots shortly of what I mean.
Win7 snapped window, with shadow
Black shadow shows around the windows.
Win7 snapped window, without shadow
as you can see here in Win7 with the windows snapped-together using allSnap - there is no red showing-through in-between the windows, at least not that I can see. Also the shadow is black when shadow is on, and not there with shadows off.
Original Win8 snapped windows with space in-between, from original post
Now, I am not entirely sure what fixed this before, it may have been jumping from the RP to Enterprize N RTM; or something may have changed the first time I un-ticked 'show window shadows'; or when I first used 'tinywindowborders.exe' from WinAero.com. But for now no matter if I tick/un-tick 'show window shadows' or install/uninstall 'tinywindowborders.exe' I do not get these massive spaces in-between borders. That's awesome!
Win8 snapped window, WITHOUT shadow
No shadow showing as per the set perimeters, however there is also a thin bit of red showing in-between the snapped windows.
Win8 snapped window, WITH shadow
I see no black shadow underneath the windows like I do in Win7/I am telling Win8 to show. There is also still a thin bit of red showing in-between the snapped windows.