2013-06-21 08:33:38:916 AU client reboot notification: user clicked Restart Later
2013-06-21 08:33:49:432 AU received handle event
2013-06-21 08:33:53:932 AU scheduling auto reboot check since no user is logged on and reboot is required.
2013-06-21 08:35:53:930 WARNING: Initiating reboot since no user logged on
Merci Microsoft…
EDIT (26/06/2013) : Vous en voulez encore ? http://support.microsoft.com/kb/970605