Hello

I'm trying to install Mountain Lion but it gets stuck at 'dsmos has arrived'

My specs are:
HP Pavilion DV7-6b10eb
2nd generation Intel Core i7-2670QM Processor (2.2 GHz)
640GB Hard Drive
6144MB DDR3 SDRAM
DVD Optical Drive
Genuine Windows 7 Ultimate (64-bit)
43.94cm (17.3") Diagonal HD+ BrightView LED Display
AMD Radeon HD 6490M (1 GB DDR5 dedicated)

I think its the graphics card, but how can this be fixed?

Thanks