Laptop screen. my laptop is compaq presario v6000 . suddenly about a quarter of the screen is

Question

my laptop is compaq presario v6000 . suddenly about a quarter of the screen is black but is has no problem on the upper 1/3 of the screen. now it does not show the whole screen. i have to use only the rest of the portion. it is very annoyying. it has a horizontal line and the lower quarter of the screen is completely black. Can you please help?????please email me at :[e-mail] at the erliest.