VRAM DELL Latitude E7450

Hi, I have a Latitude E7450.

I see in so much videos the games that this Notebook can run, games like Assassin's Creed Revelations.

But, when I want to play Assassin's Creed I, the game just doens't start cause doesn't have enought VRAM.

I see  in settings that have 128MB of VRAM, that's correct? I Google it, but I can't see that info.

And, I see that can increase the VRAM in BIOS, but I don't see this option.

Another way is creating a registry code in REGEDIT. It's safe?

Thanks