OS Wont start - dash sign flashes in the top left courner

luxor123

Honorable
Dec 19, 2013
2
0
10,510
So as told in title. Im sure its a hard-disk problem. My sister was on the pc last night and probably ignored the "Low disk space" warning. I started it up in the morning and this happened. None of these F-shortcuts work.. . Please, I need help urgently possibly without losing any of my data. Im sure it is System (C:)...