Hello all!

I am very new to BT but not Linux. Thinking same for BT as I always do with UBUNTU, I downloaded BT5 64B GNOME, burnt it through ashampoo BS and tried to boot it from DVD as live session. I got first screen as some kernal messages and prompt at boot. Pressing enter given me a list of options and a time of 30 sec.
Here problem starts. It doesn't boot at all and goes shutdown on 27 sec. remaining. I thought may be DVD corrupted, reburnt but same result. Again downloaded BT RC2 64b but this time KDE and yet same result. Calculated md5 for both iso and it is as it should be. pressing tab at selection screen flash some messages but it shut downs too. And at last I have win 7 64b as my primary OS.
my laptop has i5, nvidia 525 cuda with intel HD 1 gb and 500gb HDD (fujitsu lifebook AH531/GFO).
HELP needed.
Thank you.