Windows 7 build 6519

Windows 7 build 6519 is a Milestone 1 build of Windows 7, leaked to BetaArchive on 10 June 2008.

=New features and changes=
 * This build removed the Windows Sidebar, allowing for the gadgets to be placed freely on the desktop.
 * The notification area has been updated on both the regular Taskbar and the Superbar, allowing the user to drag hidden notifications to a separate pop-up window.
 * This build introduced transparency effects even when a window is maximized.
 * A new display dropdown menu.
 * An updated boot screen to a Vista-style aurora.
 * It is the earliest leaked build to create a "System Reserved" partition, which is used to store the Windows Boot Manager, its boot configuration data (BCD) file, and Windows Recovery Environment. In this build, it is 500MB compared to the 100MB of later builds (and is something that persists up to the latest Windows 10 build).
 * This build also extended the Windows 7 references into more areas of the operating system, as they were only present as installation identifiers on the boot manager and Recovery Environment in build 6469.
 * This build is the earliest leaked build to remove the free disk space information in the about dialog, which was present since Windows 1.0.

USB 3.0
When installing this build on modern hardware with USB, you must disable USB 3.0 (xHCI) in the BIOS, even if RTM Windows Vista installs fine with it enabled and the drive plugged into the 2.0 ports, as the installer will show an error message that Windows cannot read files.