Changed settings, black screen after minutes.

BeastEmperor - Heavens Tear

I changed my settings to high to see what the game would look like, it got laggy and my screen went black. Alt tab / Alt+ctrl+del didn't work at all, so I have to restart my laptop. I logged on and changed the settings back, yet after a couple minutes, the same thing happens. I also hit default, same thing. Does anyone know how to help?

Edit: Now im getting a red screen after 10 minutes. T_T. If anyone solves this problem for me, they get free coin in Heavens Tear ;P.