when i start my pc when the first screen i see the resultion is small but when it gets to log in screen its good how di i change the resultion screen size of the first screen

thats the screen thats small and the log in screen and when i log in all thats good only that screen pls help me someone thanks the graphic card is gtx 680 thanks im not sure wht topic this goes in It worked perfectly one day I didn't read the nividia 3d thing and i didn't read and i unstalled the drivers and that change and then later installed it back after how do I fix this? Thanks