Toshiba laptop black screen with bliking cursor

[viccivic080910]

my toshiba satellite L3550-S7901 runs, but i only get a black screen with a blinking cursor. That is all. what do i need to do? I already changed the RAM sticks with two new ones, thinking that it might have been the ram that was currupted.

 

[bellomycr]

need to mark partition as active and rewrite the mbr use the ubcd to do so and burn it as an iso if u need steps email me at bellomycr@aol.com

 

[Jqualls91]

need to mark partition as active and rewrite the mbr use the ubcd to do so and burn it as an iso if u need steps email me at bellomycr@aol.com

can you email me how to do that at Jonathan.W.Qualls@gmail.com? it would be the greatest help.