This was today March/10/2011 at 8:15am It not only happen to me, another computer at the office was restarted with no clue about reason. After that i checked the System Restore panel and I found that a “Critical Update” was installed a few minutes before the restart. This means that we can’t control some updates? Main problem here was that all my opened windows were closed and my unsaved work was lost.!!! Who can be blamed for this?