vista instillation failed

hello,
i am trying to install vista for more than one month but everytime it fails.
everything is going well, after 3rd restart it says vista is preparing for
the firsttime and then the screen goes black and there is not any response.
i am using xp now. and i am installing on toshiba labtop that is vista
capable.
i istalled it to an other pc using same dvd but on my labtop it
fails(actually it does not give any error but screens goes black and doesnot
response.).

i am gone crazyy. thanks for your help....