Is this a screenshot of the Windows Update screen from Windows 8?
Check out the leaked Windows 8 screenshots here!
The screenshot originaters from a notorious leak, who goes by the name of Zukona, who is well known for publishing reliable information on builds. This screenshot, which appears to show a new "restart if required" option in Windows Update is allegedly from the 6.2.7930.0.winmain_win8m2.110217-1825 build of Windows 8.
(Thanks to all for the tip, via WinRumors)