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.

This is the first build of Windows 8 that drops support for processors without PAE, SSE2 and NX, as running on these processors will result in a black screen with error code 0x5D. Alongside this, the wallpaper first introduced in build 8375 had its color temperature and saturation slightly adjusted.

An ARM version of this build was showcased on the Channel 9 blog post titled "Developing for Windows on ARM", but it remains unreleased as of today.

Timebomb
Unlike other Windows 8 builds, it contains a broken timebomb and can be installed on the current date.

Transparency effects in the Windows Basic theme
When using the Windows Basic (Aero Lite) 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, then 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) Switch to the other personalization window that was opened at the start, uncheck and re-check the "Enable transparency" option and then click on the "Save changes" button. This will cause transparency effects to take effect.