Windows 7 build 6519

Windows 7 build 6519 is a Milestone 1 build of Windows 7, leaked to BetaArchive on 2008-06-10. 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. It is also the first build to identify itself as "Windows 7", albeit still using Windows Vista branding in the Preinstallation Environment, and updated the boot screen to a Vista-style aurora. This build also has transparency effects even when a window is maximized. This build also includes a new display dropdown menu.

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)

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.