hp EliteBook 8470p Intel HD 4000 graphic card MP4 video 1080p and some game are not working properly

I have hp EliteBook 8470p i5-3320m , 8GB ram , Intel HD 4000 graphic card. Problem is MP4 video 1080p and some are not working properly .

1, How can i check i have discrete graphics card of AMD Radeon 7570M or not ? as it is not shown in bios and windows device manager ?

2,It is possible to upgarde discrete graphic card ?

3, Is there any option to chage share memory of intel graphic card 4000?

4,If i upgrade 8GB ram to 16GB ram it will be improve graphics quality or not ?