Can someone help me fix my computer?

I have a acer computer. When I start it up I see the acer logo and i see it say starting windows then after that the screen goes blank. I can hear the sound it makes at start up but no picture asking for my password but i can enter it and it still makes the sound but no picture. Can someone please help me fix my computer? I start school really soon and I need my computer to be working correctly. Thanks for all responses.