Windows Vista build 5212 (vbl ux dev checkin)

Windows Vista build 5212 (vbl_ux_dev_checkin) is an unleaked pre-Beta 2 build of Windows Vista. This build was shown at PDC 2005 showcasing the Digital Locker. Microsoft had released the screenshot of this build that has the taskbar (thus showing the build tag and the start orb) and sometime later, the screenshot was replaced with the one without the taskbar. However, ActiveWin managed to reupload the screenshot that has the start orb before it was replaced.

This build notably features a new Start button that has been changed to an orb, similarly to how the "Start" text was absent in x86 pre-reset Longhorn builds with the Slate theme if the sidebar was enabled. This orb would not make it into winmain until 5252 however.