While more and more details on the Windows 8.1 Spring update leak, a simple registry edit brings back the Aero Glass Theme, best known for various animation and transparency effects in Windows.
The Aero theme has been in Windows versions since Vista and Pre-release versions of Windows 8 used an updated, squared and flattened version of Aero Glass. In the final version of Windows 8, Microsoft decided to remove the Glass theme. Although the feature was removed, the code apparently was left behind.
And now an user on Betaarchive has posted a method to enable it again. By adding a key to the Windows registry the Aero Glass theme is enabled again on Windows 8.1. Using regedit the following key can be added [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\DWM] with the value, “HideBlur”=dword:00000001 . While this enables Glass, it will be far from perfect, users report it’s buggy.
Microsoft changed it mind on Windows 8 several times now, after the update Windows 8.1 boots directly to the desktop, Microsoft has been adding a start menu like feature and it would be no surprise if also the Aero Glass theme will end up in upcoming versions of the OS again.
Thanks to @BAV0 for pointing out the original source.