Computer boots but doesnt show the users info

Hello, helpppps ineed this pc for youtube



i choose boot bye disc it boots completly until it hits the user thing and just shows a screen walpaper and mouse and if u put a disc iin it acts like itresponds .. and its mising all user info ,,,,,,,,,,,,,, but when i try boot normauly it just turns black afteer the winxp bootupscreen and displays a mouse it has a gamingmoutherbord from 2001 that works