I just to want ask what happened to my Acer Laptop i3 with a video card Geforce 710M I recently had a windows 8 OS and i upgraded it to windows 8.1 by using market. It says that after downloading and installing it. It says it's ready to use. i restarted it and opened again and ask for my windows Microsoft account and i signed in after signing in, i watched some movie form my DVD and shout it down. when i'm opening it again in the morning the black screen appeared and the arrow mouse is there but it never get to the windows logo or desktop what do i need to do? please i need your help. I want to return it to windows 8 without losing a file on Drive C. Thank you