As the title says, I am unable to boot into BT5 R1. As soon as I select Default or Default with Text Mode, the system hangs at the following screen. Please see the screenshot below:

After this nothing happens.

My Laptop Configuration

Laptop: Dell XPS 17
Graphic Card: NVidia GT 555M
Processor: Intel Core i7 -2670QM

I wanted to Dual Boot Win 7 with BackTrack 5 R1 and met with this problem while booting BT5 R1 Gnome 64-bit Edition. Please suggest me what to do next...Thank you