What settings did you change? I found a funky work around to get OpenGL working on fullscreen windowed borderless. Start the game in 1680x1050 (or lower), once its open, go to task manager and find KSP. Right click it, minimize, then maximize. Puts it into fullscreen windowed borderless. Edit: Forgot to mention, the workout is really sub-optimal. You have to go into regedit and manually change the resolution back to 1680x1050 every time you restart KSP.