Is PZ OpenGL game?

[City Builder]

So, for some reason my computer no longer wants to play any games that use OpenGL, instead of seeing the game screens it never refreshes and I get a black or white screen. If I can force a game into fullscreen I can use OpenGL games.

I'm assuming that Project Zomboid uses OpenGL instead of DirectX, so is there a way to either force the game to run full screen, or does anybody happen to know why it is that my computer would refuse to play games NON-Fullscreen when those games use OpenGL?

Thanks

[City Builder]

Thanks. Didn't think it was working at first as it took so long to load up but it finally did load up the game in full screen and was playable for the most part.