So I have a windows 8 Acer laptop and well I turned it on and it worked completely fine until i clicked on the document sign and everything froze, then it said a error came up with a sad face "" but bigger, so I turned it on again and it came up with boot disk not found or something. Then I turned it on again to find that the word "diagnosing pc" I left it for about 2-3 hours yet nothing happens. Any help would be greatly appricieatted