My computer (acer) kept freezing and had a problem saying that windows couldnt check for updates. So i decided to restore it back to factory settings. Half way through the system restore the screen went black and said 'Disk read error occourd press ctrl + alt + del to restart. I pressed the buttons as described but computer resets and goes back onto the screen i have also tried to press F8 & F12 at the start up screen but nothing works i also do not have the windows vista disk. PLEASE HELP!!!