nvidea motherboard

ok so when i first turn on my computer, a display of my motherboard appears and then it runs through the bios and stuff. last night my pc was working just great. this morning i turned it on and it just stayed on this screen, there is no way i can get to the os because it doesnt load. is something unplugged or could something of gotten corrupt? please help i built this computer and i really dont want to have to get a new part.