WHATS WRONG WITH MY COMPAQ LAPTOP!!!!?

ok, well, when my computer starts up, it like makes the microsoft logo, then it will go blank for a few moments with this small white dash in the corner blinking (like this: _) then it would usually take me to my users and let me pick one and log on. but now it is stuck on the blank screen with that with dash blinking on and off. i tried f5, ctrl+alt+delete, fn+f4, and i have taken the battery out and let it died and all that stuff but it still stays at that balnk screen with the white dash. and then i called tech support but they didnt help cus my waranty expiered so they arent allowed to help me :( and my waranty thing doesnt involve like how my computer works and stuff so idk. plz help :( thx