Black Screen! Help!

I've been searching all over the internet about this and everybody has a similar problem but not the same as mine. So I was playing Sims 2 :D and it crashed. So I turned it of by the power button. Why I turned it on again it started booting the first screen and afterwards it was just a black screen with a little underscore flashing in the upper left corner. I waited and the it told me to press ctrl+alt+dlt. It restarted. And I turned it on and off and on and off ... And while I was writing this happend. D: I love my PC but I'm no pro