Game freaks out on display mode change

For one, why is it that every time I start up the game, it won't go windowed fullscreen mode as I've set it up to? It always has my windows task bar over the game? This forces me to change display mode and revert back to windowed fullscreen but then the freaking game freezes, it changes the display mode to windowed only and keeps freezing up. I have to spend a good 5 minutes (sometimes more) cos sometimes the game just crashes. What in the hell happened? This freezing BS wasn't happening before.....