Windows 8 build 8400

Windows 8 build 8400 is the official Release Preview build of Windows 8. This build was released officially by Microsoft on 31 May 2012.

Timebomb
It is one of the notable Windows 8 builds to not activate the timebomb if you install it on the current date.

Transparency effects in the Windows Basic theme
When using the Windows Basic visual style, transparency effects can be enabled by means of a bug in the Personalization Control Panel. To do so:
 * 1) Right-click the desktop and open up Personalization. Now click on the "Window Color" link given at the bottom of the window. Keep the window open.
 * 2) Open a separate personalization window and apply the Windows Basic theme.
 * 3) Go back to the other personalization window that you opened at the start, uncheck "Enable transparency" option and then re-check it. Click on "Save changes" button. This will cause "glass" effects.