Cant factory Reset me Toshiba

Hello, I am having a hard time trying to factory reset this Toshiba Satellite C670D. I wanna reset it because everytime I open it, the desktop either opens up, but I cant click on anything since its all frozen, or the desktop gets erased and there is nothing on the screen but a black or blue screen. Now when I try to hold 0 and power to factory reset, nothing happens. However, when I click on F8 and click on repair computer, there are all the options BUT the "factory reset". Instead of factory reset option, there is command prompt instead. What can I do?